upendra iti yaṁ viduḥ

marutvan-Marutvan; ca-also; jayantah-Jayanta; ca-and; marutvatyah-from Marutvati; babhuvatuh-took birth; jayantah-Jayanta; vasudeva-amsah-an expansion of Vasudeva; upendrah-Upendra; iti-thus; yam-whom; viduh-they know.