Question 23 - Did Saul know David before or not?

1 Samuel 16:19-22 NKJV - "Therefore Saul sent messengers to Jesse, and said, "Send me your son David, who is with the sheep." And Jesse took a donkey loaded with bread, a skin of wine, and a young goat, and sent them by his son David to Saul. So David came to Saul and stood before him. And he loved him greatly, and he became his armorbearer. Then Saul sent to Jesse, saying, "Please let David stand before me, for he has found favor in my sight.""

           1 Samuel 17:55-56 NKJV - "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." So the king said, "Inquire whose son this young man is.""

Answer:

Even these days also, when we meet a person whom we have already seen in different places, we have the doubt, “Is he or not” as it is difficult to recognize. In our relatives now and then, we see the children of our blood relatives. Even though we have capacity to recognize them as the son / the daughter of so and so person, in some special situations, when we meet them in special places, we are in confusion to recognize them that whose son is he?  When the head of the Philistine, the powerful warrior was in the hand of David, Saul should have been put a question to rectify his doubt. Had he the valor who did such a great deed truly? In this, Saul saw young David as Harp Player and armourbearer in 1Samuel 16:19-21. Now, Saul saw David’s valor that grew up in strength, age, and physique. Before this, he saw him as a normal man. After this he saw his valor and rectified his doubt.