1 Samuel 18:25-27

25Then Saul said, “Thus you will say to David, ‘The king desires no bridal dowry except 100 foreskins of the Philistines—to take vengeance on the king’s enemies.’” So Saul schemed to make David fall by the hand of the Philistines.

26When his courtiers told David these words, the word seemed right in David’s eyes to become the king’s son-in-law. Before the days were fulfilled,

27David had risen, gone with his men and killed 200 Philistine men. Then David brought their foreskins and gave them in full number to the king—to become the king’s son-in-law. So Saul gave him Michal his daughter as a wife.