Khandogya-Upanishad: Fifth Prapathaka, Sixteenth Khanda
1. Then he said to Budila Asvatarasvi, “O Vaiyaghrapadya, whom do you meditate on as the Self?” He replied: “Water only, venerable king.” He said; “The Self which you meditate on is the Vaisvanara Self, called Rayi (wealth). Therefore are you wealthy and flourishing.
2. “You eat food and see your desire, and whoever thus meditates on that Vaisvanara Self, eats food and sees his desire, and has Vedic glory in his house.
“That, however, is but the bladder of the Self, and your bladder would have burst, if you had not come to me.”