Khandogya-Upanishad: Third Prapathaka, Seventh Khanda
1. On the second of these nectars the Rudras live, with Indra at their head. True, the Devas do not eat or drink, but they enjoy by seeing the nectar.
2. They enter into that white colour, and they rise from that colour.
3. He who thus knows this nectar, becomes one of the Rudras, with Indra at their head, he sees the nectar and rejoices. And he, having entered that colour, rises again from that colour.
4. So long as the sun rises in the east and sets in the west, twice as long does it rise in the south and set in the north; and so long does he follow the sovereign supremacy of the Rudras.