1 Samuel 17:50-58

Thus David prevailed over the Philistine with a sling and a stone, and he struck the Philistine and killed him; but there was no sword in David’s hand. Then David ran and stood over the Philistine and took his sword and drew it out of its sheath and killed him, and cut off his head with it. When the Philistines saw that their champion was dead, they fled. The men of Israel and Judah arose and shouted and pursued the Philistines as far as the valley, and to the gates of Ekron. And the slain Philistines lay along the way to Shaaraim, even to Gath and Ekron. The sons of Israel returned from chasing the Philistines and plundered their camps. Then David took the Philistine’s head and brought it to Jerusalem, but he put his weapons in his tent. Now when Saul saw David going out against the Philistine, he said to Abner the commander of the army, “Abner, whose son is this young man?” And Abner said, “By your life, O king, I do not know.” The king said, “You inquire whose son the youth is.” So when David returned from killing the Philistine, Abner took him and brought him before Saul with the Philistine’s head in his hand. Saul said to him, “Whose son are you, young man?” And David answered, “I am the son of your servant Jesse the Bethlehemite.”