Śrīla Rūpa Gosvāmī, the younger brother of Sanātana Gosvāmī, went to Prayāga, the modern city of Allahabad, with his younger brother Vallabha. When the two brothers heard that Lord Śrī Caitanya Mahāprabhu was staying there, they both became very much pleased and went to see the Lord. At that time the Lord was on His way to visit the temple of Bindu Mādhava. On the way to the temple the Lord was chanting and dancing, and thousands of people were following Him. Some were crying and some were laughing, some were dancing and some were singing, and some were falling on the ground, offering obeisances to the Lord. And all of them were roaring the holy name: "Kṛṣṇa! Kṛṣṇa!" It is said that in spite of being at the confluence of the rivers Ganges and Yamunā, Prayāga was never flooded until the appearance of Caitanya Mahāprabhu, at which time the city was overflooded by love of Kṛṣṇa.
The two brothers, Rūpa Gosvāmī and Vallabha, stayed aloof in an uncrowded place and witnessed the great crowd and wonderful scene. When the Lord danced, He raised His arms and shouted, "Haribol! Haribol!" The people all about Him were astonished to see His activities. Indeed, the wonderful scene is difficult to describe.
After visiting the temple, the Lord accepted prasādam (food offered to the Deity) at the house of a Deccanist (southern) brāhmaṇa with whom He was acquainted. While sitting alone at the brāhmaṇa's home, the Lord was visited by Rūpa Gosvāmī and Vallabha. From a distance the two brothers fell down on the ground to offer obeisances, and they chanted many Sanskrit verses from the scriptures. When the Lord saw Rūpa Gosvāmī offering obeisances before Him, He became very much pleased and said, "My dear Rūpa, please get up." The Lord then informed Rūpa Gosvāmī of the causeless mercy of Kṛṣṇa upon him, for Kṛṣṇa had just delivered him from the materialistic way of life, which is based simply on pounds-shillings-pence.
The Lord accepted the two brothers as His devotees, and He cited a verse from the scriptures stating that the Lord will not accept a brāhmaṇa who has studied the four Vedas if he is not a devotee but He will accept someone from a very low family if he is a pure devotee. Then the Lord embraced the two brothers, and out of His causeless mercy He touched their heads with His lotus feet. Blessed in this way, the brothers offered prayers to the Lord in their own words. The prayers indicated that Lord Śrī Kṛṣṇa Caitanya Mahāprabhu was Kṛṣṇa Himself, that He had assumed a fair-complexioned form (gaurāṅga), and that He was the most munificent incarnation of Kṛṣṇa because He was distributing love of Kṛṣṇa. Śrīla Rūpa Gosvāmī also recited a verse later found in the book Govinda-līlāmṛta (1.2):
- yo ’jñāna-mattaṁ bhuvanaṁ dayālur
- ullāghayann apy akarot pramattam
- sva-prema-sampat-sudhayādbhutehaṁ
- śrī-kṛṣṇa-caitanyam amuṁ prapadye
"Let me surrender unto the lotus feet of Sri Kṛṣṇa Caitanya Mahāprabhu, who is the greatest, most merciful Personality of Godhead. He delivers those who are merged in ignorance and offers them the highest gift, love of Kṛṣṇa, and thus makes them mad after Kṛṣṇa consciousness."
After this incident, Vallabha Bhaṭṭa invited the Lord to go to the other side of the Ganges, and the Lord went. On this trip Rūpa Gosvāmī accompanied the Lord, and, indeed, wherever the Lord went Rūpa Gosvāmī would follow Him and stay with Him. Because the Lord felt inconvenienced in crowded places, He asked Rūpa Gosvāmī to accompany Him to a place on the banks of the Ganges known as Daśāśvamedha-ghāṭa. For ten days He instructed Rūpa Gosvāmī about the truth of Kṛṣṇa, the principles of devotional service, and the transcendental mellows (relationships with Kṛṣṇa). All of this was described in full detail so that in the future Rūpa Gosvāmī could distribute the science of Kṛṣṇa in his book Bhakti-rasāmṛta-sindhu. Śrīla Rūpa Gosvāmī described this incident in the first verse of Bhakti-rasāmṛta-sindhu, in which he speaks of the causeless mercy of the Lord upon him.
The Supreme Lord is cognizant and all-powerful, and by His causeless mercy He empowers a living entity to receive His mercy. People in general, being under the spell of conditioned life, are averse to rendering devotional service and practicing Kṛṣṇa consciousness. They are unaware of the teachings of Kṛṣṇa consciousness, which reveal one's eternal relationship with the Supreme Personality of Godhead, the process by which one can return to the spiritual world, and the ultimate goal of life, which is to return home, back to Godhead. Because these things are unknown to the conditioned soul, Lord Caitanya, out of His causeless mercy, instructed Rūpa Gosvāmī in the principles of devotional service. Later, Rūpa Gosvāmī distributed this science to the people in general.