Khandogya-Upanishad: Eighth Prapathaka, Ninth Khanda
1. But Indra, before he had returned to the Devas, saw this difficulty. As this self (the shadow in the water) is well adorned, when the body is well adorned, well dressed, when the body is well dressed, well cleaned, if the body is well cleaned, that self will also be blind, if the body is blind, lame, if the body is lame, crippled, if the body is crippled, and will perish in fact as soon as the body perishes. Therefore I see no good in this (doctrine).
2. Taking fuel in his hand he came again as a pupil to Pragâpati. Pragâpati said to him: “Maghavat (Indra), as you went away with Virokana, satisfied in your heart, for what purpose did you come back?”
He said: “Sir, as this self (the shadow) is well adorned, when the body is well adorned, well dressed, when the body is well dressed, well cleaned, if the body is well cleaned, that self will also be blind, if the body is blind, lame, if the body is lame, crippled, if the body is crippled, and will perish in fact as soon as the body perishes. Therefore I see no good in this (doctrine).”
3. “So it is indeed, Maghavat,” replied Pragâpati; “but I shall explain him (the true Self) further to you. Live with me another thirty-two years.”
He lived with him another thirty-two years, and then Pragâpati said: