Srimad Bhagavatam Canto 06, Chapter 18, Text 55

SB 6.18.55

badham ity abhyupetyatha
 diti rajan maha-manah
kasyapad garbham adhatta
 vratam cañjo dadhara sa
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
O King Pariksit, Diti, the wife of Kasyapa, agreed to undergo the purificatory process known as pumsavana. “Yes,” she said, “I shall do everything according to your instructions.” With great jubilation she became pregnant, having taken semen from Kasyapa, and faithfully began discharging the vow.
Srimad Bhagavatam Canto 06, Chapter 18, Text 54
Srimad Bhagavatam Canto 06, Chapter 18, Text 56