Vishnupurana 1.21.p14

1.21.p14

O best of ascetics, when there was a quarrel amongst the Gandharvas, serpents, Dānavas and gods, Diti, having lost all her children, propitiated Kasyapa, Being perfectly adored by her, Kasyapa, the foremost of the ascetics, promised her a boon and Diti prayed for it in the shape of a valiant son capable of destroying Indra, O excellent Muni, he granted his spouse that boon. And having granted her that boon Kasyapa said—"You shall give birth to a son who shall destroy Sakra, if with pious thoughts and a pure body, you carry the babe in your womb for a hundred years". Having said this the ascetic Kasyapa remained with her and she conceived being perfectly pure. Knowing that this conception was for his own destruction, Indra the lord of immortals, came to her and attended upon her with humility. And the slayer of Pāka wanted there to thwart her intention. At last in the last year of the century he found out an opportunity. Diti, without washing her feet, went to bed. And when she was asleep the wielder of the thunder-bolt entered into her womb and severed the embryo into seven pieces.