1 Samuel 17:55 KJV
And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, whose son is this youth? And Abner said, As thy soul liveth, O king, I cannot tell.
1 Samuel 17:53–57 KJV Chapter Context
53
And the children of Israel returned from chasing after the Philistines, and they spoiled their tents.
54
And David took the head of the Philistine, and brought it to Jerusalem; but he put his armour in his tent.
55
And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, whose son is this youth? And Abner said, As thy soul liveth, O king, I cannot tell.
56
And the king said, Enquire thou whose son the stripling is.
57
And 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.