Śrī Caitanya Mahāprabhu, the Supreme Personality of Godhead, personally told Sanātana Gosvāmī about Lord Kṛṣṇa's real identity. He also told him about the Lord's conjugal love, His personal opulence and the mellows of devotional service. All these truths were explained to Sanātana Gosvāmī by the Lord Himself out of His causeless mercy.