SB 9.9.38

ata ūrdhvaṁ sa tatyāja
 strī-sukhaṁ karmaṇāprajāḥ
vasiṣṭhas tad-anujñāto
 madayantyāṁ prajām adhāt
Synonyms: 
ataḥ — in this way; ūrdhvam — in the near future; saḥ — he, the King; tatyāja — gave up; strī-sukham — the happiness of sexual intercourse; karmaṇā — by destiny; aprajāḥ — remained sonless; vasiṣṭhaḥ — the great saint Vasiṣṭha; tat-anujñātaḥ — being permitted by the King to beget a son; madayantyām — in the womb of Madayantī, King Saudāsa’s wife; prajām — a child; adhāt — begot.
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.