Prasna-upanishad, Fourth Question

4.1Then Sauryayanin Gargya asked: 'Sir, What are they that sleep in this man, and what are they that are awake in him? What power (deva) is it that sees dreams? Whose is the happiness? On what do all these depend?'

4.2He replied: 'O Gargya, As all the rays of the sun, when it sets, are gathered up in that disc of light, and as they, when the sun rises again and again, come forth, so is all this (all the senses) gathered up in the highest faculty (deva), the mind. Therefore at that time that man does not hear, see, smell, taste, touch, he does not speak, he does not take, does not enjoy, does not evacuate, does not move about. He sleeps, that is what people say.

4.3The fires of the pranas are, as it were, awake in that town (the body). The Apana is the Garhapatya fire, the Vyana the Anvaharyapakana fire; and because it is taken out of the Garhapatya fire, which is fire for taking out, therefore the Prana is the Ahavaniya fire. Now the Apana is identified with the Garhapatya fire, no reason being given except afterwards, when it is said that the Prana is the Ahavaniya fire, being taken out of the Garhapatya, here called pranayana, in the same manner as the prana proceeds in sleep from the apana. The Vyana is identified with the Dakshinagni, the Southern fire, because it issues from the heart through an aperture on the right.

4.4Because it carries equally these two oblations, the out-breathing and the in-breathing, the Samana is he (the Hotri priest). The mind is the sacrificer, the Udana is the reward of the sacrifice, and it leads the sacrificer every day (in deep sleep) to Brahman.

4.5There that god (the mind) enjoys in sleep greatness. What has been seen, he sees again; what has been heard, he hears again; what has been enjoyed in different countries and quarters, he enjoys again; what has been seen and not seen, heard and not heard, enjoyed and not enjoyed, he sees it all; he, being all, sees.

4.6And when he is overpowered by light, then that god sees no dreams, and at that time that happiness arises in his body.

4.7And, O friend, as birds go to a tree to roost, thus all this rests in the Highest Atman,--

4.8The earth and its subtile elements, the water and its subtile elements, the light and its subtile elements, the air and its subtile elements, the ether and its subtile elements; the eye and what can be seen, the ear and what can be heard, the nose and what can be smelled, the taste and what can be tasted, the skin and what can be touched, the voice and what can be spoken, the hands and what can be grasped, the feet and what can be walked, the mind and what can be perceived, intellect (buddhi) and what can be conceived, personality and what can be personified, thought and what can be thought, light and what can be lighted up, the Prana and what is to be supported by it.

4.9For he it is who sees, hears, smells, tastes, perceives, conceives, acts, he whose essence is knowledge, the person, and he dwells in the highest, indestructible Self,--

4.10He who knows that indestructible being, obtains (what is) the highest and indestructible, he without a shadow, without a body, without colour, bright--,yes, O friend, he who knows it, becomes all-knowing, becomes all. On this there is this Sloka:

4.11He, O friend, who knows that indestructible being wherein the true knower, the vital spirits (pranas), together with all the powers (deva), and the elements rest, he, being all-knowing, has penetrated all.'