There is no difference between meditating on the eternal forms of Rādhā-Kṛṣṇa and chanting the mahā-mantra, Hare Kṛṣṇa. As for Kṛṣṇa’s meditation, He had no alternative but to meditate on Himself. The object of meditation is Brahman, Paramātmā or the Supreme Personality of Godhead, but Kṛṣṇa Himself is all three: He is the Supreme Personality of Godhead, Bhagavān; the localized Paramātmā is His plenary partial expansion; and the all-pervading Brahman effulgence is the personal rays of His transcendental body. Therefore Kṛṣṇa is always one, and for Him there is no differentiation.
Kṛṣṇa Book, Volume 2-Chapter 15 (Excerpt)
