yuvam-both of you (Prsni and Sutapa); vai-indeed; brahmana adistau-ordered by Lord Brahma (who is known as Pitamaha, the father of the Prajapatis); praja-sarge-in the creation of progeny; yada-when; tatah-thereafter; sanniyamya-keeping under full control; indriya-gramam-the senses; tepathe-underwent; paramam-very great; tapah-austerity.