Frequent practice of meditation on Brahman is necessary as there is instruction to that effect in the Sruti. The Purvapakshin maintains that it is to be observed once only as in the case of Prayaja offerings and the like. The present Sutra refutes this view and says that hearing, etc., must be repeated till one attains knowledge of Brahman or direct Self-realisation, just as paddy is husked till we get rice. There is the necessity of repetition till there is dawn of knowledge of Brahman. The repetition of mental acts of reflection and meditation eventually leads to direct Self-realisation.
Repetition is to be performed because scripture gives repeated instruction.
Thus in the Chh. Here Svetaketu is taught the mystery about Brahman nine times before he understood it. The analogy of the Prayaja is faulty. It is not to the point at all because there is the Adrishta which is the result gives fruit at some particular future time in the next world. But here the result is directly realised.