1 Samuel 17:33-36

ISV(i) 33 Saul told David, “You can’t go against this Philistine and fight him. You are only a young man, but he has been a warrior since his youth.”
34 David told Saul, “Your servant has been a shepherd for his father. When a lion or bear came and took a lamb from the flock, 35 I would go out after it, strike it down, and rescue the lamb from its mouth. Then when it rose up against me, I would grab it by its fur, strike it down, and kill it. 36 Your servant has struck down both lions and bears, and this uncircumcised Philistine will be like one of them, since he defied the armies of the living God.”