Khandogya-Upanishad: Eighth Prapathaka, Fourteenth Khanda
1. He who is called ether (akasa) is the revealer of all forms and names. That within which these forms and names are contained is the Brahman, the Immortal, the Self
I come to the hall of Pragâpati, to the house; I am the glorious among Brahmans, glorious among princes, glorious among men. I obtained that glory, I am glorious among the glorious. May I never go to the white, toothless, yet devouring, white abode; may I never go to it.