Bhagavatapurana 9.8.15

9.8.15

yo 'samañjasa ityuktaḥ sa keśinyā nṛpātmajaḥ /
tasya putro 'ṃśumān nāma pitāmahahite rataḥ //

15. O king, he, who is called Asamanjasa, was the son of Kesini and his son was Amsuman who devoted himself to the achievement of his grandfather’s purpose.