1 Samuel 17:38-50

And Saul clad David with his apparel, and he put a helmet of brass upon his head, and he clad him with a coat of mail. And David girded his sword upon his apparel, and he assayed to go; for he had not proved it. And David said unto Saul, I cannot go with these; for I have not proved them. And David put them off him. And he took his staff in his hand, and chose him five smooth stones out of the brook, and put them in the shepherd’s bag which he had, even in his wallet; and his sling was in his hand: and he drew near to the Philistine. And the Philistine came on and drew near unto David; and the man that bare the shield went before him. And when the Philistine looked about, and saw David, he disdained him; for he was but a youth, and ruddy, and withal of a fair countenance. And the Philistine said unto David, Am I a dog, that thou comest to me with staves? And the Philistine cursed David by his gods. And the Philistine said to David, Come to me, and I will give thy flesh unto the birds of the heavens, and to the beasts of the field. Then said David to the Philistine, Thou comest to me with a sword, and with a spear, and with a javelin: but I come to thee in the name of Jehovah of hosts, the God of the armies of Israel, whom thou hast defied. This day will Jehovah deliver thee into my hand; and I will smite thee, and take thy head from off thee; and I will give the dead bodies of the host of the Philistines this day unto the birds of the heavens, and to the wild beasts of the earth; that all the earth may know that there is a God in Israel, and that all this assembly may know that Jehovah saveth not with sword and spear: for the battle is Jehovah’s, and he will give you into our hand. And it came to pass, when the Philistine arose, and came and drew nigh to meet David, that David hastened, and ran toward the army to meet the Philistine. And David put his hand in his bag, and took thence a stone, and slang it, and smote the Philistine in his forehead; and the stone sank into his forehead, and he fell upon his face to the earth. So David prevailed over the Philistine with a sling and with a stone, and smote the Philistine, and slew him; but there was no sword in the hand of David.