1 Samuel 17:32-37 NLT

32 “Don’t worry about this Philistine,” David told Saul. “I’ll go fight him!”
33 “Don’t be ridiculous!” Saul replied. “There’s no way you can fight this Philistine and possibly win! You’re only a boy, and he’s been a man of war since his youth.”
34 But David persisted. “I have been taking care of my father’s sheep and goats,” he said. “When a lion or a bear comes to steal a lamb from the flock,
35 I go after it with a club and rescue the lamb from its mouth. If the animal turns on me, I catch it by the jaw and club it to death.
36 I have done this to both lions and bears, and I’ll do it to this pagan Philistine, too, for he has defied the armies of the living God!
37 The who rescued me from the claws of the lion and the bear will rescue me from this Philistine!” Saul finally consented. “All right, go ahead,” he said. “And may the be with you!”