Bhagavatapurana 1.3.5

1.3.5

etan nānāvatārāṇāṃ nidhānaṃ bījam avyayam /
yasyāṃśāṃśena sṛjyante devatiryaṅnarādayaḥ //

5. This is the abode to which all return on the completion of the world’s work, and this is the unchanging seed (source) of His various Avataras; and with the Amsas of this Amsa, the gods, men, animals, etc., are created (through Brahma, Marichi, etc).