1.4 To him the teacher said: Prajapati, the Creator, was desirous of progeny. He performed austerities, and having performed austerities, created the pair, the moon (rayi) and the sun (prana). He said to Himself: “These two should produce creatures for Me in manifold ways.”
1.5 The sun Is, indeed, prana, life; the moon is rayi, food. Food is, indeed, all this—what has form and what is formless.
2.2 To the disciple he said: Space, akasa, verily is that god—the wind, fire, water, earth, speech, mind, eye, and ear, as well. These, having manifested their glory, said boastfully: “We [each of us] support this body and uphold it.”
2.3 To them prana, the chiefmost said: “Do not fall into delusion. I alone, dividing myself into five parts, support this body and uphold it.
3.3 This prana is born of Atman. As a shadow is cast by a person, so this prana is, by Atman. Through the activity of the mind it comes into this body.
4.9 He, verily, it is who sees, feels, hears, smells, tastes, thinks, and knows. He is the doer, the intelligent self, the purusha. He is established in the Highest, the imperishable Atman.
4.10 He who knows that imperishable Being, bright, without shadow, without body, without colour, verily attains the Supreme, the undecaying Purusha. O my good friend, he who knows Atman becomes all-knowing, becomes all. About it there is the following verse:
4.11 He, O friend, who knows that imperishable Being wherein rests the intelligent self, together with the gods, the pranas, and the elements —he becomes all-knowing and enters into all.
~Prasna Upanishad (tr-Nikhilananda)