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.