1 Samuel 17:39-40

David put on Saul’s sword and tried to walk around, but he was not used to all the armor Saul had put on him. He said to Saul, “I can’t go in this, because I’m not used to it.” Then David took it all off. He took his stick in his hand and chose five smooth stones from a stream. He put them in his shepherd’s bag and grabbed his sling. Then he went to meet the Philistine.