Khandogya-Upanishad: Fourth Prapathaka, Second Khanda
2. “Raikva, here are six hundred cows, a necklace, and a carriage with mules; teach me the deity which you worship.”
3. The other replied: “Fie, necklace and carriage be thine, O Sudra, together with the cows.”
Then Ganasruti Pautrayana took again a thousand cows, a necklace, a carriage with mules, and his own daughter, and went to him.
4. He said to him: “Raikva, there are a thousand cows, a necklace, a carriage with mules, this wife, and this village in which thou dwellest. Sir, teach me!”
5. He, opening her mouth, said: “You have brought these (cows and other presents), O Sudra, but only by that mouth did you make me speak.” These are the Raikva-parna villages in the country of the Mahavrishas (mahapunyas) where Raikva dwelt under him. And he said to him: