Jaiminīya (Talavakāra) Brāhmaṇa 0.17

There are, indeed, two wombs: one is the divine womb, the other is the human womb. There are, indeed, two worlds: one is the world of the gods, the other is the world of humans. That which is the human womb, that is the human world; it is a woman's generative organ. From this, offspring are born. Therefore one should desire a beautiful wife, thinking, 'May my self come into being in a beautiful [womb].' And therefore one should guard one's wife, thinking, 'Lest another come into being in my womb, in my world.' For when he is about to come into being, the breaths enter first; then the semen is emitted. He develops towards these breaths, these spaces. Therefore, although the semen is the same, of whatever sort [the father] is, of such sort [the child] is born. Now, this divine womb, the world of the gods, is the Āhavanīya [fire]. This is indeed the divine womb, the world of the gods. Therefore, if one should offer into the Gārhapatya [fire], they would consider him as doing what is undone. When he makes an offering, when he does good, in this very divine womb he pours himself. That self of his comes into being in yonder Āditya. He who knows thus has two selves and two wombs. He who does not know this has only one self and one womb. When he who knows thus departs from this world—

—his breath ascends first. It announces to the gods the measure [of his deeds]: 'So much good was done by him, so much evil.' Then this one ascends upward along with the smoke. The seasons are his doorkeepers. He should declare to them with this [formula]: 'From the far-seeing, O seasons, the semen has been brought, formed in a half-month, from the generative [father] possessed of fathers. Set me, such as I am, in a male who is an agent; poured from a male who is an agent into a mother, being born and reborn through the twelfth [month], as the thirteenth, an intercalary month—I know that together, I know that in response; as such, O seasons, lead me to the immortal.' Then the seasons lead him. Just as one who knows [leads] one who knows, just as one who understands [leads] one who understands, so indeed the seasons lead him. They let him pass through. He comes to this one who burns [above]. To him who has arrived, he asks: 'Who are you?' He who proclaims himself by name or by lineage, to him he says: 'This self of yours which was in me, this is that of yours.' When he has received that self, the seasons, having run together, seize him by the feet and drag him away. Day and night take possession of his world. Therefore he should declare with this [formula]: 'Who (Ko) am I; heaven (suvas) are you. As such, I have come to you, the heavenly, to heaven.' 'Who' (Ka) is indeed Prajāpati.