CC Ādi 2.8

svayaṁ bhagavān kṛṣṇa, viṣṇu-paratattva
pūrṇa-jñāna pūrṇānanda parama mahattva
Word for word: 
svayam — Himself; bhagavān — the Supreme Personality of Godhead; kṛṣṇa — Lord Kṛṣṇa; viṣṇu — of all-pervading Viṣṇu; para-tattva — the ultimate truth; pūrṇa-jñāna — full knowledge; pūrṇa-ānanda — full bliss; parama — supreme; mahattva — greatness.
Translation: 
Kṛṣṇa, the original form of the Personality of Godhead, is the summum bonum of the all-pervading Viṣṇu. He is all-perfect knowledge and all-perfect bliss. He is the Supreme Transcendence.