C. F. Keil and Franz Delitzsch on 1 Samuel 18:24-25

1Sa 18:24-25

When this answer was reported to the king, he sent word through his courtiers what the price was for which he would give him his daughter. He required no dowry (see at Gen 34:12), but only a hundred foreskins of the Philistines, i.e., the slaughter of a hundred Philistines, and the proof that this had been done, to avenge himself upon the enemies of the king; whereas, as the writer observes, Saul supposed that he should thus cause David to fall, i.e., bring about his death by the hand of the Philistines.