1 Samuel 18:27-30

David rose up and went, he and his men, and struck down two hundred men among the Philistines. Then David brought their foreskins, and they gave them in full number to the king, that he might become the king’s son-in-law. So Saul gave him Michal his daughter for a wife. When Saul saw and knew that the LORD was with David, and that Michal, Saul’s daughter, loved him, then Saul was even more afraid of David. Thus Saul was David’s enemy continually. Then the commanders of the Philistines went out to battle, and it happened as often as they went out, that David behaved himself more wisely than all the servants of Saul. So his name was highly esteemed.