Exodus 17:9-13

9So Moses said to 1Joshua, “Choose men for us and go out, fight against Amalek. Tomorrow I will station myself on the top of the hill with 2the staff of God in my hand.” 10Joshua did as Moses 3told him, 4and fought against Amalek; and Moses, Aaron, and 5Hur went up to the top of the hill. 11So it came about when Moses held his hand up, that Israel prevailed, and when he let his hand 6down, Amalek prevailed. 12But Moses’ hands were heavy. Then they took a stone and put it under him, and he sat on it; and Aaron and Hur 7supported his hands, one on one side and one on the other. Thus his hands were steady until the sun set. 13So Joshua 8overwhelmed Amalek and his people with the edge of the sword.