1 Samuel 17:31-36

Yet what David said was told to Saul, and he sent for David. David said to Saul, “Don’t let anyone be discouraged. I, your servant, will go and fight this Philistine!” Saul answered, “You can’t go out against this Philistine and fight him. You’re only a boy. Goliath has been a warrior since he was a young man.” But David said to Saul, “I, your servant, have been keeping my father’s sheep. When a lion or bear came and took a sheep from the flock, I would chase it. I would attack it and save the sheep from its mouth. When it attacked me, I caught it by its fur and hit it and killed it. I, your servant, have killed both a lion and a bear! This uncircumcised Philistine will be like them, because he has spoken against the armies of the living God.