1 Samuel 17:55-58

55When Saul saw David going 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.”

56So the king said, “Inquire whose son this young man is.”

57Then, as David returned from the slaughter of the Philistine, Abner took him and brought him before Saul with the head of the Philistine in his hand.

58And Saul said to him, “Whose son are you, young man?” So David answered, “I am the son of your servant Jesse the Bethlehemite.”