AITAREYA UPANISHAD • II.1

In man, indeed, this the Self first becomes an embryo. That which is the seed retas is the strength and vigor tejas gathered from all the limbs of the body. One bears this self within one's own self. When he pours this into a woman, he causes it to be born. This is his first birth. 1

It becomes one with the woman’s self, just as her own limb does. Therefore, it does not hurt her. She nourishes this self of his that has entered into her. 2

She, the nourisher, must be nourished. The woman bears the embryo. In the period before the child's birth, the father nourishes it; by nourishing the child from the moment of birth onward, he is actually nourishing his own self, for the continuation of these worlds. For thus are these worlds continued. This is his second birth. 3

This self the son, being the representative of the father, is substituted for him for the performance of pious deeds. Then his other self the father, having performed his duties and reached the end of his lifespan, departs from this world. Departing from here, he is born again. This is his third birth. 4

Concerning this, it was said by the Seer Rishi:
"While I was yet in the womb, I knew all the births of the gods. A hundred iron citadels original: "pur ayasir"; a metaphor for the constraints of the physical body and previous lives held me down, but like a hawk, I forced my way out with speed." Vamadeva spoke this even while lying in the womb. 5

He Vamadeva, knowing this, ascended aloft after the destruction of the body. In that heavenly world svarga, he obtained all desires and became immortal—yes, he became immortal. 6

AITAREYA UPANISHAD • III.1

Who is this one whom we meditate upon as the Self Atman? Which one is the Self? Is it that by which one sees, or that by which one hears, or that by which one smells scents, or that by which one articulates speech, or that by which one discriminates between the sweet and the unsweet? 1

That which is the heart and the mind...