1 Samuel 17:48-50

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.