So the king said, "Inquire whose son this young man is."
1 Samuel 17:56
Surrounding context
17:55 When 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."
17:56 So the king said, "Inquire whose son this young man is."
17:57 Then, 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.