tam sambarah kama-rupi
hrtva tokam anirdasam
sa viditvatmanah satrum
prasyodanvaty agad grham
The demon Sambara, who could assume any form he desired, kidnapped the infant before He was even ten days old. Understanding Pradyumna to be his enemy, Sambara threw Him into the sea and then returned home.
Srila Visvanatha Cakravarti points out that according to the Visnu Purana, Pradyumna was kidnapped on the sixth day after His birth.