1 Samuel 17:55-58

As soon as Saul saw David go out against the Philistine, he said to Abner, the commander of the army, “Abner, whose son is this youth?” And Abner said, “As your soul lives, O king, I do not know.” And the king said, “Inquire whose son the boy is.” And as soon as David returned from the striking down of the Philistine, Abner took him, and brought him before Saul with the head of the Philistine in his hand. And Saul said to him, “Whose son are you, young man?” And David answered, “I am the son of your servant Jesse the Bethlehemite.”