Khandogya-Upanishad: Fifth Prapathaka, Tenth Khanda
1. “Those who know this (even though they still be grihasthas, householders) and those who in the forest follow faith and austerities (the vanaprasthas, and of the parivragakas those who do not yet know the Highest Brahman) go to light (arkis), from light to day, from day to the light half of the moon, from the light half of the moon to the six months when the sun goes to the north, from the six months when the sun goes to the north to the year, from the year to the sun, from the sun to the moon, from the moon to the lightning. There is a person not human,—
2. “He leads them to Brahman (the conditioned Brahman). This is the path of the Devas.
3. “But they who living in a village practice (a life of) sacrifices, works of public utility, and alms, they go to the smoke, from smoke to night, from night to the dark half of the moon, from the dark half of the moon to the six months when the sun goes to the south. But they do not reach the year.
4. “From the months they go to the world of the fathers, from the world of the fathers to the ether, from the ether to the moon. That is Soma, the king. Here they are loved (eaten) by the Devas, yes, the Devas love (eat) them.
5. “Having dwelt there, till their (good) works are consumed, they return again that way as they came, to the ether, from the ether to the air. Then the sacrificer, having become air, becomes smoke, having become smoke, he becomes mist,
6. “Having become mist, he becomes a cloud, having become a cloud, he rains down. Then he is born as rice and corn, herbs and trees, sesamum and beans. From thence the escape is beset with most difficulties. For whoever the persons may be that eat the food, and beget offspring, he henceforth becomes like unto them.
7. “Those whose conduct has been good, will quickly attain some good birth, the birth of a Brahmana, or a Kshatriya, or a Vaisya. But those whose conduct has been evil, will quickly attain an evil birth, the birth of a dog, or a hog, or a Kandala.
8. “On neither of these two ways those small creatures (flies, worms, &c.) are continually returning of whom it may be said, Live and die. Theirs is a third place.
“Therefore that world never becomes full” (cf.V, 3, 2). “Hence let a man take care to himself! And thus it is said in the following Sloka:—
9. “A man who steals gold, who drinks spirits, who dishonours his Guru's bed, who kills a Brahman, these four fall, and as a fifth he who associates with them.
10. “But he who thus knows the five fires is not defiled by sin even though he associates with them. He who knows this, is pure, clean, and obtains the world of the blessed, yea, he obtains the world of the blessed.”