CC Ādi 5.79

ete cāṁśa-kalāḥ puṁsaḥ
kṛṣṇas tu bhagavān svayam
indrāri-vyākulaṁ lokaṁ
mṛḍayanti yuge yuge
Word for word: 
ete — all these; ca — also; aṁśa-kalāḥ — part or part of the part; puṁsaḥ — of the Supreme Person; kṛṣṇaḥ tu — but Lord Kṛṣṇa; bhagavān — the original Personality of Godhead; svayam — Himself; indra-ari — the demons; vyākulam — disturbed; lokam — all the planets; mṛḍayanti — makes them happy; yuge yuge — in different millenniums.
Translation: 
“All these incarnations of Godhead are either plenary portions or parts of the plenary portions of the puruṣa-avatāras. But Kṛṣṇa is the Supreme Personality of Godhead Himself. In every age He protects the world through His different features when the world is disturbed by the enemies of Indra.”
Purport: 

This quotation is from Śrīmad-Bhāgavatam (1.3.28).