1 Samuel 17

45Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a shield: but I come to thee in the name of the LORD of hosts, the God of the armies of Israel, whom thou hast defied.
49And David put his hand in his bag, and took thence a stone, and slang it , and smote the Philistine in his forehead, that the stone sunk into his forehead; and he fell upon his face to the earth.