maha-raurava haite toma karila uddhara
krpara samudra krsna gambhira apara"
maha-raurava haite—from the deepest hellish condition of life; toma—you; karila uddhara—has delivered; krpara samudra—the ocean of mercy; krsna—Krsna; gambhira—very grave; apara—unlimitedly.
"My dear Sanatana, Krsna has saved you from Maharaurava, life's deepest hell. He is an ocean of mercy, and His activities are very grave."
As stated in Bhagavad-gita, isvarah sarva-bhutanam hrd-dese 'rjuna tisthati. Staying within everyone's heart, Lord Krsna 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 (dadami buddhi-yogam tam yena mam upayanti te). Sri Caitanya Mahaprabhu is telling Sanatana Gosvami how merciful the Lord is. Sanatana Gosvami 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 Krsna's mercy he came to find such association distasteful. Therefore he left them. As stated by Srinivasa Acarya: tyaktva turnam asesa-man-dala-pati-srenim sada tuccha-vat. Krsna enlightened Sanatana Gosvami in such a way that he was able to give up his exalted post as minister. Thinking his material position insignificant, Sanatana was prepared to become a mendicant. Appreciating the activities of Sanatana Gosvami, Sri Caitanya Mahaprabhu praised his action and thanked Krsna for His mercy upon him.
Link to this page: https://prabhupadabooks.com/cc/madhya/20/63