According to the Vedic process, one can get a son through semen ( śukra ), one can get a bona fide disciple through initiation ( sāvitra ), or one can get a son or disciple through the fire of sacrifice ( yajṣa ). Thus when Mahārāja Purūravā generated the fire by rubbing the araṇis, the fire became his son. Either by semen, by initiation or by yajṣa one may get a son. The Vedic mantra oṁkāra, or praṇava, consisting of the letters a-u-m, can call each of these three methods into existence. Therefore the words nirmanthanāj jātaḥ indicate that by the rubbing of the araṇis a son was born.