1 Samuel 17:38-50

Then Saul dressed David in his own tunic. He put a coat of armor on him and a bronze helmet on his head. David fastened on his sword over the tunic and tried walking around, because he was not used to them. “I cannot go in these,” he said to Saul, “because I am not used to them.” So he took them off. Then he took his staff in his hand, chose five smooth stones from the stream, put them in the pouch of his shepherd’s bag and, with his sling in his hand, approached the Philistine. Meanwhile, the Philistine, with his shield bearer in front of him, kept coming closer to David. He looked David over and saw that he was little more than a boy, glowing with health and handsome, and he despised him. He said to David, “Am I a dog, that you come at me with sticks?” And the Philistine cursed David by his gods. “Come here,” he said, “and I’ll give your flesh to the birds and the wild animals!” David said to the Philistine, “You come against me with sword and spear and javelin, but I come against you in the name of the LORD Almighty, the God of the armies of Israel, whom you have defied. This day the LORD will deliver you into my hands, and I’ll strike you down and cut off your head. This very day I will give the carcasses of the Philistine army to the birds and the wild animals, and the whole world will know that there is a God in Israel. All those gathered here will know that it is not by sword or spear that the LORD saves; for the battle is the LORD’s, and he will give all of you into our hands.” As the Philistine moved closer to attack him, David ran quickly toward the battle line to meet him. Reaching into his bag and taking out a stone, he slung it and struck the Philistine on the forehead. The stone sank into his forehead, and he fell facedown on the ground. So David triumphed over the Philistine with a sling and a stone; without a sword in his hand he struck down the Philistine and killed him.