Ajatashatru said: “O Balaki, when this person was asleep, where was this conscious being? Where had it gone, and from where did it return?” He then explained: “There are subtle channels called nāḍīs of the heart, extending from the heart throughout the body. They are exceedingly fine, like a hair split into a thousand parts. Within them are essences of white, black, yellow, and red hues. When a person is asleep and sees no dream whatsoever, he becomes united with Prāṇa, the vital life-force, and rests in oneness with it. At that time, speech, together with all names, merges into him; the eye, together with all forms, merges into him; the ear, together with all sounds, merges into him; and the mind, together with all thoughts, merges into him. Then, when he awakens, these faculties emerge again from that Self, just as from a blazing fire, sparks fly out in all directions. In the same way, from this Self (Ātman), the vital powers return to their respective functions; from the vital powers arise the gods, and from the gods arise the worlds. Just as a razor rests hidden within its case, or as fire lies concealed within the fire-producing wood, so does this Conscious Self (Prajñā Ātman) dwell hidden within the body. Having entered this body, He pervades it completely—from the roots of the hair to the tips of the nails."