Khandogya-Upanishad: Second Prapathaka, Seventh Khanda

1. Let a man meditate on the fivefold Saman, which is greater than great, as the prânas (senses). The hinkara is smell (nose), the prastava speech (tongue), the udgitha sight (eye), the pratihara hearing (ear), the nidhana mind. These are one greater than the other.

2. What is greater than great belongs to him, nay, he conquers the worlds which are greater than great, who knowing this meditates on the fivefold Saman, which is greater than great, as the prânas (senses).