1 Samuel 17:31-39

³¹When the words that David spoke were heard, they informed Saul, and he sent for him. ³²And David said to Saul, “May no one’s heart fail on account of him; your servant will go and fight this Philistine!” ³³But Saul said to David, “You are not able to go against this Philistine to fight him; for you are only a youth, while he has been a warrior since his youth.” ³⁴But David said to Saul, “Your servant was tending his father’s sheep. When a lion or a bear came and took a sheep from the flock, ³⁵I went out after it and attacked it, and rescued the sheep from its mouth; and when it rose up against me, I grabbed it by its mane and struck it and killed it. ³⁶Your servant has killed both the lion and the bear; and this uncircumcised Philistine will be like one of them, since he has defied the armies of the living God.” ³⁷And David said, “The Lord who saved me from the paw of the lion and the paw of the bear, He will save me from the hand of this Philistine.” So Saul said to David, “Go, and may the Lord be with you.” ³⁸Then Saul clothed David with his military attire and put a bronze helmet on his head, and outfitted him with armor. ³⁹And David strapped on his sword over his military attire and struggled at walking, for he had not trained with the armor. So David said to Saul, “I cannot go with these, because I have not trained with them.” And David took them off.