1 Samuel 17:45-52

ISV(i) 45 Then David told the Philistine, “You come at me with a sword, a spear, and a javelin, but I come to you in the name of the LORD of the Heavenly Armies, the God of the armies of Israel whom you have defied. 46 This very day the LORD will deliver you into my hand, and I’ll strike you down and remove your head from you. And this very day I’ll give the dead bodies of the Philistine army to the birds of the sky and to the animals of the earth, so that all the earth will know that there is a God in Israel, 47 and this whole congregation will know that the LORD does not deliver by sword or spear. Indeed, the battle is the LORD’s and he will give you into our hands.”
48 When the Philistine got up and came closer to meet David, David quickly ran to the battle line to meet the Philistine. 49 David reached his hand into the bag, took out a stone, slung it, and struck the Philistine in his forehead. The stone sunk into his forehead, and he fell on his face to the ground. 50 David defeated the Philistine with a sling and a stone; he struck down the Philistine and killed him, and there was no sword in David’s hand. 51 David ran and stood over the Philistine. He took the Philistine’s sword, pulled it from its sheath, killed him, and then he cut off his head with it. When the Philistines saw that their champion was dead, they fled. 52 The men of Israel and Judah got up with a shout and pursued the Philistines as far as the entrance to the valley and to the gates of Ekron. Wounded Philistines fell along the way to Shaaraim as far as Gath and Ekron.