1 Samuel 17:55

And when Saul saw David go forth against the Philistine, he said unto Abner, the captain of the host, Abner, (e) whose son [is] this youth? And Abner said, [As] thy soul liveth, O king, I cannot tell.

(e) That is, of what family and tribe is he? He had forgotten David, even though he had received so great a benefit by him.