206
Śrīmad-Bhāgavatam
[Canto 9, Ch. 14]
thought of the lower  araṇi  as Urvaśī, the upper one as himself, and the middle one as his son. A relevant Vedic  mantra  quoted herein by Viśvanātha Cakravartī 'Thākura is śamī-garbhād agniṁ mantha. A similar  mantra  is  urvaśyām urasi purūravāḥ . Purūravā wanted to have children continuously by the womb of Urvaśī. His only ambition was to have sex life with Urvaśī and thereby get a son. In other words, he had so much lust in his heart that even while performing  yajña  he thought of Urvaśī, instead of thinking of the master of  yajña , Yajñeśvara, Lord Viṣṇu.
TEXT 46
तस्य निर्मन्थनाज्जातो जातवेदा विभावसुः । 
    त्रय्या स विद्यया राज्ञा पुत्रत्वे कल्पितस्त्रिष्ठत् ॥४६॥
tasya nirmanthanāj jāto 
    jāta-vedā vibhāvasuḥ 
    trayyā sa vidyayā rājñā 
    putratve kalpitas tri-vṛt
tasya —of Purūravā;  nirmanthanāt —because of interaction;  jātaḥ —was born;  jāta-vedāḥ —meant for material enjoyment according to the Vedic principles;  vibhāvasuḥ —a fire;  trayyā —following the Vedic principles;  saḥ —the fire;  vidyayā —by such a process;  rājñā —by the King;  putratve —a son's being born;  kalpitaḥ —it so became;  tri-vṛt —the three letters  a-u-m  combined together as  oṁ .
TRANSLATION
From Purūravā's rubbing of the  araṇis  came a fire. By such a fire one can achieve all success in material enjoyment and be purified in seminal birth, initiation and in the performance of sacrifice, which are invoked with the combined letters  a-u-m . Thus the fire was considered the son of King Purūravā.
PURPORT
According to the Vedic process, one can get a son through semen ( śukra ), one can get a bona fide disciple through initiation ( sāvitra ), or