1 Samuel 17:31-33

King James Version

³¹ And when the words were heard which David spake, they rehearsed them before Saul: and he sent for him.

³² And David said to Saul, Let no man's heart fail because of him; thy servant will go and fight with this Philistine.

³³ And Saul said to David, Thou art not able to go against this Philistine to fight with him: for thou art but a youth, and he a man of war from his youth.