Bālakānda - Canto 46

Disconsolate over the death of her sons, Diti embarks on a course of austerities at Kuśaplava with the permission of her husband, Sage Kaśyapa, with the object of securing a son capable of killing Indra. The latter on coming to know of her intention serves her during the period of her consecration and, taking advantage of her falling asleep on one occasion with her head in a wrong position, and thereby transgressing the rules of purity, enters her womb and carves the foetus.