Srimad Bhagavatam Canto 10, Chapter 16, Text 35

SB 10.16.35

tapah sutaptam kim anena purvam
nirasta-manena ca mana-dena
dharmo ’tha va sarva-jananukampaya
yato bhavams tusyati sarva-jivah
Did our husband carefully perform austerities in a previous life, with his mind free of pride and full of respect for others? Is that why You are pleased with him? Or did he in some previous existence carefully execute religious duties with compassion for all living beings, and is that why You, the life of all living beings, are now satisfied with him?
In this regard Srila Prabhupada comments in his Krsna, the Supreme Personality of Godhead, Chapter Sixteen: “The Nagapatnis confirm that one cannot come in contact with Krsna without having executed pious activities in devotional service in his previous lives. As Lord Caitanya advised in His Siksastaka, one has to execute devotional service by humbly chanting the Hare Krsna mantra, thinking oneself lower than the straw in the street and not expecting honor for himself but offering all kinds of honor to others. The Nagapatnis were astonished that, although Kaliya had the body of a serpent as the result of grievous sinful activities, at the same time he was in contact with the Lord to the extent that the Lord’s lotus feet were touching his hoods. Certainly this was not the ordinary result of pious activities. These two contradictory facts astonished them.”
Srimad Bhagavatam Canto 10, Chapter 16, Text 34
Srimad Bhagavatam Canto 10, Chapter 16, Text 36