He said to him: 'No one but a true Brâhmana would thus speak out. Go and fetch fuel, friend, I shall initiate you. You have not swerved from the truth. Having initiated him, he chose four hundred lean and weak cows, and said: 'Tend these, friend.' He drove them out and said to himself, 'I shall not return unless I bring back a thousand.' He dwelt a number of years (in the forest), and when the cows had become a thousand,

In plain words: The teacher says only a true Brahmin (a person of real spiritual worth) would speak so honestly, and he accepts Satyakama as a student. He gives him 400 thin, weak cows to look after. Satyakama promises himself not to come back until they become a thousand, and he lives in the forest for years caring for them.