1 Samuel 17:31-33

31What David said was overheard and reported to Saul, and Saul sent for him.

32David said to Saul, “Let no one lose heart on account of this Philistine; your servant will go and fight him.”

33Saul replied, “You are not able to go out against this Philistine and fight him; you are only a young man, and he has been a warrior from his youth.”