Although the Sambhodra Tantra does not mention it, the small word Ah should be visualized with a head. According to the pith-instruction given in the Tantra of Bde-mchog, all the four words should be visualized with the half-moon head, the Thig-le and Na-da melting like the female Bodhisattva about to weep. This teaching is important because it produces and will enhance the Great Bliss.

If the Yogi visualizes the word as very bright and glowing, he will be able easily to overcome drowsiness and promote his illuminative experience of Samadhi.

When any visualized object is meditated upon, the yogi should put all his mind into the subtle object as if his mind (or rather his whole being) enters into the object. He

should never visualize the object as if he merely sees it before him[r_nar:68]. For the correct practice, mind and object become as one; thus the experience of the unification of mind and Thig-le will come to pass, and, the gathering of the prana will become easy. In the practice of this meditation one should neither overstrain nor be too lax in his effort. Overstrain or laziness will bring drowsiness and distractions; therefore, the yogi should avoid both extremes.

The beginner should not meditate on the three words above the heart center for too long; he should meditate on them for only a short while, and devote most of this time to concentrating on the small Ah. If he finds it difficult to concentrate on the minute object, he should visualize it a little larger. When a larger picture can be stabilized in the mind, the yogi will then be able to visualize smaller or more subtle objects.

The purpose of practicing the Heat Yoga is to produce the Four Blisses. When the Bodhi-Heart in the nerves begins melting and the two pranas[r_nar:69] start gathering at the head Chakra, the (first) Bliss [ananda] begins to arise. Thereafter, the Bodhi-Heart begins to disperse into the nerves. When the Bodhi-Heart gathers at the Throat Center the (second) Extreme-Bliss [paramananda] arises; then the Bodhi-Heart disperses again through the different nerves, and when it is gathered at the Heart Center, the (third) Superb Bliss [viramananda] arises. Again, the Bodhi-Hearth disperses through the nerves, and when it is gathered at the Navel Center, the (fourth) Innate Bliss [sahajananda] arises [**]. Following this

if one meditates upon the words in the center of the Central Channel in the four Chakras, the mind-prana will be easily gathered at the four centers; thus, the Four Blisses will arise from the four centers. It is necessary for the Yogi to recognize these Four Blisses in experience.