Caitanya Caritamrita Adi Lila 01 13 By HH Jayapataka Swami at ISKCON Mayapur.
bhaktāvatāram īśaṁ tam
Because He is nondifferent from Hari, the Supreme Lord, He is called Advaita, and because He propagates the cult of devotion, He is called Ācārya. He is the Lord and the incarnation of the Lord’s devotee. Therefore I take shelter of Him.