Exodus 17:10–13
10Joshua did what Moses told him and went out to fight the Amalekites. Meanwhile, Moses, Aaron, and Hur climbed to the top of the hill. 11Whenever Moses raised his hand, Israel prevailed. But whenever he lowered his hand, Amalek prevailed. 12Moses' hands grew heavy, so they brought a stone and set it under him to sit on. Aaron stood on one side and Hur on the other, each holding up one of his hands. His hands stayed steady until sunset. 13Joshua defeated Amalek and his people with the sword.