1 Samuel 17:32-39

David said to Saul, “Let no man’s heart fail on account of him; your servant will go and fight with this Philistine.” Then Saul said to David, “You are not able to go against this Philistine to fight with him; for you are but a youth while he has been a warrior from his youth.” But David said to Saul, “Your servant was tending his father’s sheep. When a lion or a bear came and took a lamb from the flock, I went out after him and attacked him, and rescued it from his mouth; and when he rose up against me, I seized him by his beard and struck him and killed him. Your servant has killed both the lion and the bear; and this uncircumcised Philistine will be like one of them, since he has taunted the armies of the living God.” And David said, “The LORD who delivered me from the paw of the lion and from the paw of the bear, He will deliver me from the hand of this Philistine.” And Saul said to David, “Go, and may the LORD be with you.” Then Saul clothed David with his garments and put a bronze helmet on his head, and he clothed him with armor. David girded his sword over his armor and tried to walk, for he had not tested them. So David said to Saul, “I cannot go with these, for I have not tested them.” And David took them off.