Brihadaranyaka-Upanishad: First Adhyâya, Second Brahmana
1. In the beginning there was nothing (to be perceived) here whatsoever. By Death indeed all this was concealed—by hunger; for death is hunger. Death (the first being) thought, “Let me have a body.” Then he moved about, worshipping. From him thus worshipping water was produced. And he said: “Verily, there appeared to me, while I worshipped (arkate), water (ka).” This is why water is called ar-ka. Surely there is water (or pleasure) for him who thus knows the reason why water is called arka.
2. Verily water is arka. And what was there as the froth of the water, that was hardened, and became the earth. On that earth he (Death) rested, and from him, thus resting and heated, Agni (Virâg) proceeded, full of light.
3. That being divided itself threefold, Aditya (the sun) as the third, and vayu (the air) as the third. That spirit (prâna) became threefold. The head was the Eastern quarter, and the arms this and that quarter (i.e. the N. E. and S. E., on the left and right sides). Then the tail was the Western quarter, and the two legs this and that quarter (i.e. the N. W. and S. W.) The sides were the Southern and Northern quarters, the back heaven, the belly the sky, the dust the earth. Thus he (Mrityu, as arka) stands firm in the water, and he who knows this stands firm wherever he goes.
4. He desired, “Let a second body be born of me,” and he (Death or Hunger) embraced Speech in his mind. Then the seed became the year. Before that time there was no year. Speech bore him so long as a year, and after that time sent him forth. Then when he was born, he (Death) opened his mouth, as if to swallow him. He cried Bhan! and that became speech.
5. He thought, “If I kill him, I shall have but little food.” He therefore brought forth by that speech and by that body (the year) all whatsoever exists, the Rik, the Yagus, the saman, the metres, the sacrifices, men, and animals.
And whatever he (Death) brought forth, that he resolved to eat (ad). Verily because he eats everything, therefore is Aditi (Death) called Aditi. He who thus knows why Aditi is called Aditi, becomes an eater of everything, and everything becomes his food.
6. He desired to sacrifice again with a greater sacrifice. He toiled and performed penance. And while he toiled and performed penance, glorious power went out of him. Verily glorious power means the senses (prâna). Then when the senses had gone out, the body took to swelling (sva-yitum), and mind was in the body.
7. He desired that this body should be fit for sacrifice (medhya), and that he should be embodied by it. Then he became a horse (asva), because it swelled (asvat), and was fit for sacrifice (medhya); and this is why the horse-sacrifice is called Asva-medha.
Verily he who knows him thus, knows the Asva-medha. Then, letting the horse free, he thought, and at the end of a year he offered it up for himself, while he gave up the (other) animals to the deities. Therefore the sacrificers offered up the purified horse belonging to Pragâpati, (as dedicated) to all the deities.
Verily the shining sun is the Asvamedha-sacrifice, and his body is the year; Agni is the sacrificial fire (arka), and these worlds are his bodies. These two are the sacrificial fire and the Asvamedha-sacrifice, and they are again one deity, viz. Death. He (who knows this) overcomes another death, death does not reach him, death is his Self, he becomes one of those deities.