1 Samuel 17:33-37

33Saul replied, “You are not able to go out against this Philistine and fight him; you are only a young man, and he has been a warrior from his youth.” 34But David said to Saul, “Your servant has been keeping his father’s sheep. When a lion or a bear came and carried off a sheep from the flock, 35I went after it, struck it and rescued the sheep from its mouth. When it turned on me, I seized it by its hair, struck it and killed it. 36Your servant has killed both the lion and the bear; this uncircumcised Philistine will be like one of them, because he has defied the armies of the living God.

37The 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 the LORD be with you.”