This is to be explained in two parts. First, following the Heat Yoga, other Yogas are to be discussed in general. Second, each of these Yogas will be individually considered. Now, the first:
Of this school, the teaching on Entering-into-the-Central Channel through the practice of Dumo is very clear, but, the practices and instructions on the Illusory Body and Light are very obscure. These teachings are very difficult to understand; however, I shall reveal some unique pith-instructions that I have obtained.
These instructions on the Illusory Body and Light Yoga are obtained from the source of Gsan Adus given by Apags-pa, father and son. According to their teaching, before the process of entering, remaining, and dissolving into the Central Channel by the life-Prana, the three steps of the Manifestation, Augmentation, and Attainment of the Peaceful-Mind Samadhi74 can never be attained.
The mind-prana that perfects the genuine wisdom of the Peaceful-Mind-State is also the means through which the genuine Illusory Body is practiced. These teachings are clearly given in the pith-instructions on the Gsan Adus and are also found in the teaching of the Five Steps of the Marpa School. Therefore, though the teaching of Light Yoga and Illusory Body are not clearly given in Naropa's Six Yogas, relying on the instructions of Apags-pa, the explanations are given here:
In the Commentary of the Epitome of the Five Steps of the Marpa School, the stanza says:
"At first, (the yogi will) see the mirage-like visions
With the five-coloured light shining.
The next vision he will see is a moon.
The third one is the flowing light of the sun.
Then the vision of the brink appears.
Through this process manifests the Illusory-Body
That is manifested by the mind-prana."
The vision of moonlight shining from a cloudless sky appears; this is a stage of Manifestation. Then the glowing light of the sun shines in the sky; this is the stage of Augmentation. Then the brink period that appears like the dark sky before dawn comes in sight; this is the stage of Attainment. After the emergence of these stages, the real Illusory Body-with-light that is produced by the Mind-Prana of the Peaceful-Mind Teaching (will come to pass); but this point is not clearly stated in the Six Yogas.
Among the numerous teachings of the Illusory Body, one is to meditate on the shadow-like nature of the self-body. First let someone praise and then insult you and observe the reactions of pleasure and resentment. Thus the crude form of the delusory thoughts75 are subdued; this is the practice of the Impure Illusory Body. Another practice is called the Pure Illusory Body Yoga. That is to meditate on the illusory-like self-Buddha figure and let another person praise and insult you and observe the reaction of pleasure and displeasure, until an indifferent feeling toward both praise and insult arises. But this practice is not a special practice; it is the common practice of the highest Yoga and other general teachings.
Other teachings of the Illusory Body are the Three-Steps
Apags-pa pith-instruction is thus afforded, and the incompleteness of the Illusory-Body teaching of the Marpa School is also discussed fully.
Again, there are instructions such as given here: the teaching of the Two-in-One-with-Learning, the teaching of the Two-in-One-without-Learning, the principle of the four steps: Manifestation, Augmentation, Attainment and Great Light. Especially, the instructions on the following steps are given: How the illusory body is transformed from the mind-prana; how one can enter into the Absolute Light after making the Illusory Body; in what manner the Manifestation, Augmentation, Voidness, etc., come in sight; how the Two-in-One-with-Learning76 (Body) is transformed after the Absolute-Light is stabilized and how through it the Two-in-One-without-Learning Body can be established how, if the Yogi practices the Light-of-Sleep, he is able to make the prana enter into the Central Channel during the awakening state; then how the four Voids will successively appear as light through his capability of gathering the prana of Roma and Rkyang-ma in the Heart Center (after the light state); and how the Illusory Body of Buddha will appear in the dream—in this stage, even if the Illusory Body of Buddha does not appear in the dream, the yogi will have no doubt.
Through the power of the prana's entrance into the Central Channel, one is able to hold the light of sleep;
or, if one has attained the general Samadhis of Mahayana or Hinayana, one can also apply his Samadhi's power in the sleeping state. Thus, the deep-sleep-Samadhi state can be brought into the weaker-sleeping-state Samadhi. There is no clear explanation here on the differences of these various experiences though the various approaches. Therefore, one should carefully discriminate between the holding-of-dream through prana power and the holding-of-dream through desire; and between the coming of death-light and sleep-light through the prana power and through the power of the strong will. How the Sambhogakaya is manifested in the Bardo state should also be studied. If one wants to know this in detail, one may study the instructions of Apags-pa who provides much information.
In the practice of holding the Light-of-Sleep and the practice of holding the dream state, though the power of prana, the first step is to grasp the Light-of-Sleep and then manipulate the dream state.
If one is not able to gather the prana into the Central Channel, but with a very strong will or intention sets one's mind upon the recognizing of the dream state during the awakening time, throughout exertion of will power a Samadhi of sleeping state will arise. However, this cannot be called a decisive or actual Light-of-Sleep state.
If through both the inner and outer daytime practice, one is able to proceed with the entering, remaining, and dissolving process in the Central Channel, the well-known Four Blisses and Four Voids will arise. Then the identity of Bliss-Void during the emergence of the Innate-Born can be practised. Eventually the Illusory Body will arise. By means of this practice, one will be able to impress the Bliss-Void feeling on all manifestations at all times. Thus the
accomplishment in this life and puts his hope in the moment of death, he must have the ability of holding the light with prana and must practice this teaching of Illusory Body of Dream. Thus he will be able to identify the Illusory Body of Bardo. Without these practices
it would be impossible to do so; therefore, these two instructions are unique and of great importance.
The instructions on the actual practice of the Illusory Body and the Light Yoga follow:
In addition to the teachings given in the last chapter—the Tantric teaching of the perfect Illusory Body, the teaching of the light-of-awakening-from sleep, the teachings for the time of the reversed processes, there are other ways of practice found in the commentaries of the great teachers, which I will now relate in this chapter. First the instruction on the Illusory Body practice; second, the instructions on the Light Yoga.
The teaching of the Illusory Body will be discussed in three steps: the Illusory Body practice on the manifestations; the Illusory Body practice on the dream state; and the Illusory Body practice on the Bardo state.
With a decisive understanding or View on Sūnyatā, the yogi associates this view with the Innate-Born Bliss in meditation. After the meditation period, through remembering the View and remembering that all manifestations are Buddhahood, the yogi will naturally experience, in all daily activities, the feeling that all manifestations are immanently illusory. He will also see all manifestations illustrating themselves in the forms of Mandalas. For these (capable) yogis, of course, there is no need for any visualization practices.
But in order to benefit those who cannot do the same in their meditation, the following practice is advised: In the after-meditation period, the yogi should observe the non-self nature of all Dharmas—the sentient beings and the material world—and identify his body with his image reflected from the mirror. Through this practice, the common
visions of sentient being and universe77 will appear as mirage without any substance or self-nature. If this experience can be stabilized, all manifestations will appear in the form of the two Mandalas78. With an understanding of the mirage-like nature, or with the view of the identity of non-self-nature Voidness and manifestation, the yogi observes the pure Mandala. And then he looks into the mirror and identifies the godly image there with his own body. In this way, the mirage-like nature of Buddha's body is observed.
With such an understanding, the yogi observes the Buddha's body in the mirror and concentrates upon it. Then he should think that this image of Buddha projects itself and merges with him. Since the former practice is a complete process, its power is much greater than that of the latter.
As instructed in The Five Steps, the picture of an image of Vajrasattva is reflected in a mirror so that by looking at this reflection, the yogi may observe the nature of the Illusory Body. Following this instruction, the two gurus, Marpa and Agog Lodrawa, have established this teaching to benefit those disciples who cannot quite understand the illusory nature of beings merely through hearing it explained. For that reason, this seeing-practice is given. To practice this teaching in the Arising Yoga, a specially constructed house is required; many different drugs and other materials are also needed. After all the preparations are arranged, the yogi then proceeds to observe the reflection of the image in the mirror. These instructions are found in both Marpa's and Agog's teachings.
(Generally speaking) there are two different aspects of the illusory-like and dream-like nature of all Dharmas:79 the existent-but-not-real aspect, and the manifesting-yet-void aspect.
Here, the latter aspect which refers to the Illusory Body is stressed.
The manifestation and the manifestation-void should also be distinguished; and two different kinds of voidness80 the voidness of the utter non-existent such as the never coming-into-being of the horn of the rabbit or the son of a barren woman; and the voidness of the manifesting-yet-empty. (If one has not realized the latter, one will not be able to understand the illusory nature of manifestations.)
The illusory nature of beings is illustrated through analogies. For example, the phantasm of horses and cattle conjured by the magicians does not exist in reality, but one cannot deny the apparent reality of these phenomena (as one sees them). The same holds true in the case of sentient beings (and objects, etc.) as people see them. Although there is no immanent actuality in the self-nature of beings, (through their illusory thoughts) people see manifestations as having real existence.
The manifestations considered (by ordinary beings) as things having Dharma-form (color, shape, sound, taste, etc.) have never existed. Nevertheless, the actor and the action, the hearer and the sound, the seer and the vision, etc., are continuously manifesting themselves freely. If one realizes the Two-in-One View of "existence in voidness and voidness in existence,"81 there will be no danger of falling into the extreme Realistic or Nihilistic views. Since all Dharmas are immanently void in nature, realizing their nature as void is quite sufficient; there is no need for creating a voidness through one's mind-effort, or a voidness of day, month, or year (past, present, and future).
If one meditates on this principle, all attachments and clinging to the actuality of beings will be subdued. This
profound principle (of voidness) is by no means imperceptible or unobservable. During the practice of the meditation on Reality Śūnyatā, and during the contemplation of the Right View, it (the Voidness) can definitely serve as an object of observation. It is utterly erroneous to say that the reality of Voidness cannot be seen or known, that it can never be practiced in the path, and that nothing of it can be understood, as claimed by some scholars of the old schools of Tibet.
The origin of all the conceptions of skandhas, self-natures, and symbols, is the very thought of I am! Therefore one should stress practicing the non-existence of the self-nature of beings. As the yogi perceives the "becomings" with his mind, he should appreciate the existence of manifestations in the mundane category. The existence of causations—the existence of the doer and receiver—should be confirmed within own mind. Though these causations are devoid of self-nature, they still manifest freely without any hindrances. Should a conflict between the two—the voidness and existence—appear in his mind, he should think on the principle of delusiveness, reflected by the parables of shadow, dream, etc., and reconcile the conflict.
We know that the reflection of the face in the mirror is in reality void. We also know that the reflection is caused by the conjunction of the face and mirror, and that the withdrawal of either of them will end the reflection. But the disappearance of the reflection does not mean the annihilation of the face and mirror themselves82. In the same way, though there is not one atom existing in sentient beings, the Karma-doer, the Karma-receiver, and the ripening of Karma through one's previous deeds can still take
place. We should ponder on and practice this principle; when its understanding is stabilized one may proceed to work on the practice of the Beyond-Measure-Palace, outwardly, and the Yi-Dam image (in the Mandala). Then, he should contemplate the View of the Identity of the Bliss and Void.
Through these practices, the yogi will experience all manifestations as the Bodies of Buddha, will realize these Bodies as delusory, and will find this delusiveness absorbed in the Great Bliss. These realizations will take place successively as three steps. If the yogi attains the Great Bliss in his main-meditation stage, he should pay especial attention to the observation of Śūnyatā. Thus, by concentration on Śūnyatā-Bliss the non-discriminating Wisdom will arise.
The yogi should practice the main-meditation and after-meditation stages, alternatively.83
The instruction on the Dream-Illusory Body Practice falls into four divisions: (1) how to recognize the dream; (2) how to purify and develop the dream; (3) how to overcome the rambling type of dreams and recognize them as illusory manifestations; (4) how to practice on the real nature of dream.
(1) There are two different ways to recognize or to hold the dream. The first way is recognizing and holding the dream through the power of Prana. That is, through the power which is produced by the gathering and dissolving of Prana in the Central Channel during the waking stage, the Four Voidnesses will arise. At the outset, when the light of the dream stage is realized, the yogi will be able to recognize the Four Voidnesses clearly. Through this realization, he will automatically recognize the dream (as
such). In this case, there is no need for him to practice any teachings for recognizing the dream. The second way is recognizing the dream by intention. These teachings are provided for those who do not have the power over Prana, as mentioned before. This practice is carried out by creating, in the daytime, a strong intention for recognizing the dream and concentrating on the Throat Center, etc.
Of these two (methods), the former is the unique teaching of recognizing the dream given by Tantra. The latter practice, however, is a common and general one. Here, I want to mention the so-called teaching of Matsur, of recognising the dream through concentration on the Heart Center, and the teaching of Mestson of accomplishing the same purpose by concentration on the Throat Center. Some claim that concentration on the Heart Center is for the practice of Light Yoga and that concentration on the Throat Center is for the practice of Dream Yoga. However, I think that, through the arising of the Four Voidnesses of sleep, before the dream appears, the power of Prana—which is produced by concentration on the Heart Center—will enable one to recognize the dream. Therefore it is permissible to say that concentration on the Heart Center will enable one to recognize the dream. In the case of practice through intensive intention, the yogi is not able to see the Four Voidnesses before the dream appears; therefore, concentration on the Throat Center is the right method.
In this connection, one may ask: "Since concentrating on the Throat Center is the right teaching, should we stick to it and disregard the others?" A brief discussion on this point may be helpful. Consider the case of the yogi who is able to hold (the dream) through Prana power; if he concentrates on the Throat Center during the time just
before falling into the stage of sleep, the Pranas will gather and dissolve in the Central Channel at the Throat Center. Though the yogi has raised the Four Voidnesses beforehand, (because of the diversified attention placed on the Throat Center) the Prana is neither concentrated (completely) in the Heart Center nor gathered at the Throat Center. Since the Four Voidnesses can never be revealed through practices other than meditation in the Heart Center, the yogi should concentrate on the Heart Center just on the verge of falling asleep.
However, there is an advantage in concentrating on the Throat Center. If one concentrates at the Throat Center or at the forehead, the gathering of Prana in the Heart Center will become lesser and weaker; consequently, the sleep will become very light and the awareness of mind will become clearer. If a dream is produced through meditating on the Throat Center during sleep, this dream will last longer than usual (or be more steady than the usual dream.) Furthermore, if the yogi raises a desire to have a longer dream in his sleeping state after a certain dream he has experienced, he will shortly be able, through the power derived from previous concentration on the Throat Center (during repose), to hold his mind (and produce) a dream wherein he is able to practice the meritorious (Dream Yoga) for a longer. period. For these reasons, the instruction for concentrating on the Throat Center is given.
Generally speaking, if the yogi has a sound foundation of the practice of the path, his dream is clear and he is able to recognize it frequently. In this case, he does not have to depend on the infrequent clear dreams (as do those who practice with intention). If he has strong desires in the
daytime, these will usually be (represented) in his dreams. Based on this principle, if he creates a strong desire during the day to recognize his dream, and repeatedly strengthens this desire while awake, he will, when asleep, be able to recognize the dream. This is not a very difficult practice.
If no dream whatsoever appears, there is then no way for the yogi to practice the Dream Yoga; therefore, he must use all methods to produce a dream as given in the Tantric instructions. If the dream takes place but is not clear, it will still be difficult for the yogi to practice Dream Yoga. Therefore, it is necessary to have a clear dream—clear to the point that the yogi can relate it when he awakes. To dwell in a solitary place helps to purify mind so that it will be as clear in the evening as in the morning. Then it is easy to recognize the dream. In short, this intentional practice requires a very strong desire directed toward recognizing the dream in the daytime, and only by such strong habitual thinking and awareness can the dream be recognized. Therefore, the practice in the daytime is important. Besides this, there are many teachings such as concentrating on the Throat Center, on the point between the eyebrows, visualizing certain objects and shapes, some special Prana practices, etc. Through these methods, the clearness and awareness of the mind is strengthened.
Thus, the yogi should follow these Pith-instructions of Dream Yoga, study them, and learn them well. He should rely on a guru who possesses the unmistakable experience of Dream Yoga; otherwise (if he follows the wrong instruction from the wrong guru), he may have some experiences in the beginning, but will have nothing but confusion in the end.
Once the dream is recognized, the yogi should visualize himself as his Patron Buddha, or practice the Guru Yoga together with offering-prayers. (In the dream state) the yogi should make an effort to create many clear, auspicious dreams at his own will, try to recognize them, expand them, and utilize them as an opportunity to practice various benevolent devotions. If any ominous dream occur the yogi should transform it into an auspicious one. He should pray to his Guru with great earnestness to grant him the ability to do so. In the dream state, the yogi should perform the ritual of offering the Gtormas to the Yi-Dam and protective deities, pray them to grant his wishes, etc. In his retreat-confinement,84 the yogi should work hard on these practices.
Practice during the daytime should put emphasis mainly on dwelling upon or retaining the memory of the desire (to recognize the dream at night). The yogi should think that all manifestations he beholds and all that cross his way in the waking state are (actually) in the dream state. This he does by reminding himself, "This is a dream. I now recognize it. I know that I am dreaming." With great earnestness the yogi should strengthen his wish by enhancing the desire. Thus, eventually, when the dreams appear, he will be able to recognize them and also to utilize them as a basis to exercise (the Dream Yoga practices). The yogi should not only strengthen his intention by repeatedly reminding himself of the desire during the day, but also strengthen the desire just before sleep. This will greatly increase the chance of recognizing the dream.
The instructions on the intensive practice at night are given in three divisions: first, to visualize the word-symbols in the Throat Center. When the yogi feels that he is
about to go to sleep, he should visualize that he becomes the Patron Buddha and also prays many times to his guru who is sitting upon his head. Then he should visualize a red Ah word or Oṃ word situated in the center of a red lotus with four leaves in the Central Channel of the Throat Center, This Ah or Oṃ word is the symbol of the essence of Buddha's expression upon which the yogi should concentrate without distraction. In such a manner, the yogi should enter into the state of sleep (keeping these visualizations in mind).
There is another instruction on performing this practice, i.e. to visualize five words—Oṃ, Ah, Nu, Da, Ra—in a successive order, in contrast to meditating on one red Ah word alone. This method is quite different. The (Tantra) of the Non-Twofold Victorious Illusoriness says, "Meditating on the four words—Ah, Nu, Da, Ra—in a successive order does not increase more power. It helps little; therefore, this practice may be dispensed with." To meditate on the Oṃ word at the central point is in accord with the saying of Sambhudra and other Tantras85. However, visualizing a red Ah word is also acceptable. The extremely important point is to meditate on the word at the "central point"; i.e., to meditate on the word in the Throat Center in the Central Channel. Should he be unable to recognize the dream through this visualization, he must practice many, many times. If he still cannot hold the dream, he should visualize a Thig-le [here in the sense of bindu or seed of power] at the point between the eyebrows and hold on to it.
It is difficult to recognize the dream after midnight and before dawn, for this is a period in which sleep is very deep. In the time after daybreak into and through dawn, the
sleep is usually light. During this period it is easy to recognize the dream. Then the yogi should pray to his guru, remind himself of the desire (to hold onto the dream),visualize a white glittering Thig-le at the central point between the eyebrows on his self-Yi-Dam body, and hold onto the visualization. He should also practice the Vase-Breathing exercise seven times; then he will fall asleep again. If he stresses visualizing the glittering Thig-le too much, he will not be able to sleep, or will be prone to awaken easily. In this case, he should visualize the Thig-le as a little darker in hue.
Some say that if he cannot fall into sleep because of meditating on the Throat Center, he should concentrate on the forehead, visualizing a white Thig-le there. This is very erroneous, because the forehead is a place that, if concentrated upon, causes dreams to arise, (puts consciousness in operation in opposition to the tendency to sleep). This foolish statement is akin to saying that concentration upon the Sleeping Center will make one awake. If he concentrates on the Throat Center at dawn and twilight for a long period and still cannot hold the dream, he must be a person who requires a sound, heavy sleep. For him, meditating on the Eyebrow Center will help. If by doing this, the sleep then becomes too light and he is liable to awake, or he can not fall into sleep at all, he should visualize a Thig-le within the reproductive organ and also repeatedly strengthen his desire for recognizing the dream during the daytime as mentioned before. Before sleep, he should visualize a black Thig-le in the center of the organ and practice the breathing exercise twenty-one times. Thus the destructive thoughts will be halted, and he can fall into sleep more easily. One should know that meditating on that organ is a cure for light sleep.
If through the practice [of meditating on the frontal sinus center] one still cannot subdue or overcome heavy sleep, one may follow such instructions as meditating on the month and year (visualizing the moon and sun). If by doing so, the yogi still cannot practice the Dream Yoga, he should know that only through the power of the (Wisdom)-Prana produced by the arising of the Innate Born Wisdom through the process of gathering, entering, and dissolving in the Central Channel of the Heat Yoga practice, one is able to hold a dream properly. Through the practice of intensive intention, no matter how hard one tries, he may still not be able to practice properly. Therefore, he should work hard on the superb Heat Yoga and try to lead the Pranas into the Central Channel. This is the primary practice, others being secondary.
(2) How to purify and develop the dream: There are two ways to develop the dream: the mundane way and the Buddhistic way. The principle of developing the dream is to create a dream or to transform it. The yogi may think in the dream stage that he rides on the rays of the sun and moon and journeys to the thirty-three heavens or to any place in this world. To enlarge his visions and experiences, he may conceive that he walks or flies in the sky. The Buddhistic way is to conceive that in the dream state one goes to the Pure Land of Amitabha or the heaven-land of Maitreya or the Aog-min Pure Land, etc., visiting the Buddhas and Bodhisattvas, rendering one's offerings, and hearing the Dharma from them. To be able to do this, one must have attained the mastery of Prana power. Only through the Prana power is one able to transform or create any dream state at one's own will. For those who have this mastery
these things are not difficult. For the ordinary person, however, a great deal of practice is required.
In both cases (through intensive intention and through the Prana power), the yogi sees the Buddha's Pure Land in his dream vision; however, these visions are merely the pictures the (reflections) of the Buddha's Pure Land and cannot be considered as real. In the latter case (through the exercise of Prana's power), one may receive some revelations or prophecies in dream that prove to be true. Most of them, however, are not reliable. In the former case (through intensive intention), the yogi should rely on the meritorious instructions together with some breathing exercises to practice the Dream Yoga.
The following instruction will improve the practice of Dream Yoga: When the yogi sees a man, an animal, a pillar, a vase or any other object in a dream, he should transform them by multiplying them from one to two, from two to four, to eight—up to hundreds and thousands.
(3) How to overcome the rambling type of dreams and recognize them as illusory manifestations: When the yogi one sees a fire or flood in a dream and becomes frightened, he should think to himself, recognizing the dream, "How can the fire and water of dream ever harm me?" Also, he should try to jump the fire and cross the flood. To learn the illusory nature of dream means to realize the non-existent nature of the vase, and other objects of dream-visions. This is accomplished by recognizing the dream. But one is not able, merely through the understanding, to realize the non-existence Śūnyatā of the self-nature of the dream. For instance, in the waking state, when he sees the reflection in a mirror, though he knows that the reflection
is illusory, he still cannot realize the Suchness of the reflection.
One's incapacity for recognizing the dream is like that of a child who believes the reflection of his face to be his true face; while in recognizing the dream, one is like an adult who knows the reflection is unreal although it appears to be his actual face. This example is an illustration of the underlying principle, and is a good one to express the principle of the Voidness-as-Reflection (literally the Voidness of the face-like reflection in the sense of the nonexistence of the "true" face in the reflection). According to this principle, one should know that all Dharmas are Void in their self-nature—self-nature in the sense of real self-existence. One should also understand that all Dharmas are dream-like and have no substantiality whatsoever.
With this understanding definitely in mind, the yogi should acquaint himself with the nature, manner and characteristics of the Clinging-of-Existence, and also familiarize himself with the reasons for the non-existence of this (illusory) Clinging. With such an understanding, the yogi learns that all the visions, objects, and subjects that he sees in the dream are identical with (Buddha) and the Two Mandalas; they are void in nature yet manifest (freely) as conjurations. Further, the yogi should understand that all these visions are absorbed in the bliss-void, as one has experienced during the daytime.
(4) The Practice on the real nature of dream: This is a teaching combining the Light Yoga with Dream Yoga. In the practice of this teaching, the yogi clearly visualizes (in the dream state) the self-body becoming his Yidam. From his heart, the Hūṃ word emanates rays of light that gather
all the visions in the dream and draw them back into the Hūṃ word. Then both the lower and upper part of his body melt and become absorbed into the Hūṃ word. Then the Hūṃ word also vanishes into the non-discriminating Light, upon which the yogi should concentrate his mind.
The perception-of-mind86 of the dream state is much easier to absorb than the perception-of-mind of the waking state. In the dream state, when some portion of the very coarse kind of Prana dissolves itself and gathers at the Heart Center, the dream will vanish, and one will fall into the sleeping state. This is the time in which one may recognize the Voidness; if not, through repeated practices, one will definitely be able to see the Voidness of sleep clearly. If the absorbing process87 and Void-holding become stable, this will greatly help meditation—Prana exercise, visualization, Mahamudra—in the daytime. 1f the yogi cannot recognize the Voidness-of-Sleep at the beginning stage when he first falls into sleep, he will be able through the power of recognizing the dream, to see the special Voidness.
