1 Samuel 17:30-37

Then he turned from those beside him to others in front of him and asked about the offer. The people gave him the same answer as before. What David said was overheard and reported to Saul, so he had David brought to him. David said to Saul, “Don’t let anyone be discouraged by him; your servant will go and fight this Philistine!” But Saul replied, “You can’t go fight this Philistine. You’re just a youth, and he’s been a warrior since he was young.” 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.” Then David said, “The LORD who rescued me from the paw of the lion and the paw of the bear will rescue me from the hand of this Philistine.” Saul said to David, “Go, and may the LORD be with you.”