In plain words
Foolishness is the mark of the sheep. So at some time long ago we were born and lived as sheep. In some others, stealing shows itself strongly. Stealing is the quality of the cat. From this, in some birth or other we may have been born as a cat. And then, quite commonly, restlessness is there in man a hundred per cent. This restlessness is the quality of the monkey. Before this humanity we were monkeys. The monkey's name is ‘vānara’. Now the ‘vā’ has gone. ‘Vā’ means vālam, the tail. Because he is one without that tail, they gave man the name ‘nara’. Because it has a tail, it came to be called vānara. We have lost that tail, but we have not yet lost its qualities. That is why, taking many births, we have made ourselves give up the beastliness in us to some extent. To set that beastliness on the altar called the Manas and give it to God as an offering: that is the inner fruit of this yajña.