1 Samuel 18:25

And Saul said, still with the same anxiety to attain his object, Thus shall ye say to David, The king desireth not any dowry, but an hundred foreskins of the Philistines, taken, of course, from their dead bodies, to be avenged of the king's enemies. But Saul thought to make David fall by the hand of the Philistines; he was sure that this scheme to put David out of the way could not fail.