CC Ādi 7.20-21
pūrva-premabhāṇḍārera mudrā ughāḍiyā
yata yata piye, tṛṣṇā bāḍhe anukṣaṇa
Śrī Caitanya Mahāprabhu is called mahā-vadānyāvatāra because although He is Śrī Kṛṣṇa Himself, He is even more favorably disposed to the poor fallen souls than Lord Śrī Kṛṣṇa. When Lord Śrī Kṛṣṇa Himself was personally present, He demanded that everyone surrender unto Him and promised that He would then give one all protection, but when Śrī Caitanya Mahāprabhu came to this earth with His associates, He simply distributed transcendental love of God without discrimination. Śrī Rūpa Gosvāmī, therefore, could understand that Lord Caitanya was none other than Śrī Kṛṣṇa Himself, for no one but the Supreme Personality of Godhead can distribute confidential love of the Supreme Person.