1 Samuel 17:47

45Then David said to the Philistine, “You come to me with a sword, with a spear, and with a javelin; but I come to you in the name of the LORD of Armies, the God of the armies of Israel, whom you have defied.

46Today, the LORD will deliver you into my hand. I will strike you and take your head from off you. I will give the dead bodies of the army of the Philistines today to the birds of the sky and to the wild animals of the earth, that all the earth may know that there is a God in Israel,

47and that all this assembly may know that the LORD doesn’t save with sword and spear; for the battle is the LORD’s, and he will give you into our hand.”

48When the Philistine arose, and walked and came near to meet David, David hurried and ran toward the army to meet the Philistine.

49David put his hand in his bag, took a stone and slung it, and struck the Philistine in his forehead. The stone sank into his forehead, and he fell on his face to the earth.