1 Samuel 17:48-54

48And it came to pass, when the Philistine arose, and came and advanced to meet David, that David hasted, and ran towards the ranks to meet the Philistine.

49And David put his hand into the 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 on his face to the earth.

50So David overcame the Philistine with a sling and a stone, and smote the Philistine and killed him; and there was no sword in the hand of David.

51And David ran, and stood upon the Philistine, and took his sword, and drew it out of its sheath, and killed him completely, and cut off his head with it. And when the Philistines saw that their hero was dead, they fled.

52And the men of Israel and of Judah arose, and shouted, and pursued the Philistines, until thou comest to the ravine and to the gates of Ekron. And the wounded of the Philistines fell down on the way to Shaaraim, even to Gath, and to Ekron.

53And the children of Israel returned from chasing after the Philistines, and they pillaged their camps.

54And David took the head of the Philistine and brought it to Jerusalem; but he put his armour in his tent.