mahā-raurava haite tomā karilā uddhāra
kṛpāra samudra kṛṣṇa gambhīra apāra"
mahā-raurava haite—from the deepest hellish condition of life; tomā—you; karilā uddhāra—has delivered; kṛpāra samudra—the ocean of mercy; kṛṣṇa—Kṛṣṇa; gambhīra—very grave; apāra—unlimitedly.
"My dear Sanātana, Kṛṣṇa has saved you from Mahāraurava, life's deepest hell. He is an ocean of mercy, and His activities are very grave."
As stated in Bhagavad-gītā, īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati. Staying within everyone's heart, Lord Kṛṣṇa works very gravely. No one can understand how He is working, but as soon as the Lord understands the sincere activity of a person in devotional service, He helps him in such a way that the devotee cannot understand how things are happening. If the devotee is determined to serve the Lord, the Lord is always prepared to help him (dadāmi buddhi-yogaṁ taṁ yena mām upayānti te). Śrī Caitanya Mahāprabhu is telling Sanātana Gosvāmī how merciful the Lord is. Sanātana Gosvāmī was a minister in the service of Nawab Hussain Shah. He was always mixing with people materially inclined, particularly with Mohammedans, meat-eaters. Although he was in intimate touch with them, by Kṛṣṇa's mercy he came to find such association distasteful. Therefore he left them. As stated by Śrīnivāsa Ācārya: tyaktvā tūrṇam aśeṣa-man-dala-pati-śreṇīṁ sadā tuccha-vat. Kṛṣṇa enlightened Sanātana Gosvāmī in such a way that he was able to give up his exalted post as minister. Thinking his material position insignificant, Sanātana was prepared to become a mendicant. Appreciating the activities of Sanātana Gosvāmī, Śrī Caitanya Mahāprabhu praised his action and thanked Kṛṣṇa for His mercy upon him.
Link to this page: https://prabhupadabooks.com/cc/madhya/20/63