Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 38
Sanskrit:
अत ऊर्ध्वं स तत्याज स्त्रीसुखं कर्मणाप्रजा: ।वसिष्ठस्तदनुज्ञातो मदयन्त्यां प्रजामधात् ॥ ३८ ॥
ITRANS:
ata ūrdhvaṁ sa tatyājastrī-sukhaṁ karmaṇāprajāḥvasiṣṭhas tad-anujñātomadayantyāṁ prajām adhāt
Translation:
After being thus instructed, the King gave up the future happiness of sexual intercourse and by destiny remained sonless. Later, with the King’s permission, the great saint Vasiṣṭha begot a child in the womb of Madayantī.