1 Samuel 17:48-50

When the Philistine rose and came forward to meet David, David ran quickly toward the battle line to meet the Philistine. David put his hand into his bag and took out a stone and slung it, and it struck the Philistine on his forehead. The stone penetrated his forehead, and he fell face down on the ground. So David triumphed over the Philistine with a sling and a stone, and he struck down the Philistine and killed him; but there was no sword in David’s hand.