1 Samuel 17:31-36

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.” But David said to Saul, “Your servant was tending his father’s sheep. When a lion or a bear came and took a lamb out of the flock, I went out after it and attacked it and rescued the lamb from its mouth; and when it rose up against me, I seized it by its whiskers and struck and killed it. Your servant has killed both the lion and the bear; and this uncircumcised Philistine will be like one of them, since he has taunted and defied the armies of the living God.”