1 Samuel 17:34-36

David answered Saul: “Your servant has been tending his father’s sheep. Whenever a lion or a bear came and carried off a lamb from the flock, I went after it, struck it down, and rescued the lamb from its mouth. If it reared up against me, I would grab it by its fur, strike it down, and kill it. Your servant has killed lions and bears; this uncircumcised Philistine will be like one of them, for he has defied the armies of the living God.”