Chandogya Upanishad
Prapathaka V, Khanda 15
Then he said to Gana Sârkarâkshya: 'Whom do you meditate on as the Self?' He replied: 'Ether only, venerable king.' He said: 'The Self which you meditate on is the Vaisvânara Self, called Bahula (full). Therefore you are full of offspring and wealth.