Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 20

Sanskrit:

यं मन्यसे मातुलेयं प्रियं मित्रं सुहृत्तमम् ।अकरो: सचिवं दूतं सौहृदादथ सारथिम् ॥ २० ॥

ITRANS:

yaṁ manyase mātuleyaṁpriyaṁ mitraṁ suhṛttamamakaroḥ sacivaṁ dūtaṁsauhṛdād atha sārathim

Translation:

O King, that personality whom, out of ignorance only, you thought to be your maternal cousin, your very dear friend, well-wisher, counselor, messenger, benefactor, etc., is that very Personality of Godhead Śrī Kṛṣṇa.

Purport:

Lord Śrī Kṛṣṇa, although acting as the cousin, brother, friend, well-wisher, counselor, messenger, benefactor, etc., of the Pāṇḍavas, was still the Supreme Personality of Godhead. Out of His causeless mercy and favor upon His unalloyed devotees, He performs all kinds of service, but that does not mean that He has changed His position as the Absolute Person. To think of Him as an ordinary man is the grossest type of ignorance.