Srimad Bhagavatam Canto 10, Chapter 45, Text 41

 SB 10.45.41

aste tenahrto nunam
 tac chrutva satvaram prabhuh
jalam avisya tam hatva
 napasyad udare ’rbhakam
 
Translation: 
 
“Indeed,” the ocean said, “that demon has taken him away.” Hearing this, Lord Krsna entered the ocean, found Pañcajana and killed him. But the Lord did not find the boy within the demon’s belly.
Srimad Bhagavatam Canto 10, Chapter 45, Text 40
Srimad Bhagavatam Canto 10, Chapter 45, Text 42-44