Krishn says that he had imparted knowledge of yog to Vivaswat in the beginning. Vivaswat taught it to Manu and Manu to Ikshwaku, and thus the knowledge evolved to the stage of rajas. The teacher who had imparted this knowledge was Krishn or, in other words, one who is birthless and unmanifest. A realized sage too is birthless and unmanifest. His body is but an abode in which he dwells. It is God himself who speaks through his voice. It is by some such sage that yog is imparted.
God (Krishn) is known as an outcome of yagya. He is the one into whom breath-recitation, yagya, and purificatory rites allmerge. He is the tranquillity which the worshipper experiences as an outcome of yagya, that is, with the attainment of this repose he is transformed into a sage like Krishn.