1 Samuel 18:26-27

26And his servants told David these words; and the thing was right in David's sight to be the king's son-in-law. And the days were not expired,

27when David arose and went, he and his men, and smote of the Philistines two hundred men; and David brought their foreskins, and they delivered them in full to the king, that he might be the king's son-in-law. And Saul gave him Michal his daughter as wife.