I Samuel 18:27

27 David took his men with him and went out and killed two hundred Philistines and brought back their foreskins. They counted out the full number to the king so that David might become the king's son-in-law. Then Saul gave him his daughter Michal in marriage.

27 So David and his men got up and went, and put to death two hundred of the Philistines; and David took their private parts and gave the full number of them to the king, so that he might be the king's son-in-law. And Saul gave him his daughter Michal for his wife.