Vishnupurana 1.21.26

1.21.26

ete kaśyapadāyādāḥ kīrtitāḥ sthāṇujaṅgamāḥ /
teṣāṃ putrāś ca pautrāś ca śataśo 'tha sahasraśaḥ //

These were the children of Kaśyapa, whether movable or stationary, whose descendants multiplied infinitely through successive generations. This creation, oh Brahman, took place in the second or Swárochisha Manwantara. In the present or Vaivaswata Manwantara, Brahmá being engaged at the great sacrifice instituted by Varuńa, the creation of progeny, as it is called, occurred; for he begot, as his sons, the seven Rishis, who were formerly mind-engendered; and was himself the grand-sire of the Gandharbas, serpents, Dánavas, and gods.