1 Samuel 17:29-33

But David said, “What have I done now? Was it not just a [harmless] question?” Then David turned away from Eliab to someone else and asked the same question; and the people gave him the same answer as the first time. When the words that David spoke were heard, the men reported them to Saul, and he sent for him. David said to Saul, “Let no man’s courage fail because of him (Goliath). Your servant will go out and fight with this Philistine.” Then Saul said to David, “You are not able to go against this Philistine to fight him. For you are [only] a young man and he has been a warrior since his youth.”