These Pranas (senses), when quarrelling together as to who was the best, went to Brahman and said: 'Who is the richest of us?' He replied: 'He by whose departure this body seems worst, he is the richest.'

In plain words: The body's powers, called Pranas here, argued about which of them was the best and asked Brahman, the Creator. He said the best is the one whose leaving makes the body worst off.