1 Samuel 17:40

40Then he took his [shepherd’s] staff in his hand and chose for himself five 17:40 Smooth stones offered less resistance to the air in flight and would travel with greater speed and accuracy. The sling was a pouch attached to the ends of two long leather thongs, and was a formidable weapon (as the Philistine giant was about to discover).smooth stones out of the stream bed, and put them in his shepherd’s bag which he had, that is, in his shepherd’s pouch. With his sling in his hand, he approached the Philistine.