Exodus 17:8-13

8At Rephidim, Amalek came and fought against Israel.

9Moses said to Joshua, “Select some men for us and go fight against Amalek. Tomorrow I will stand on the hilltop with God’s staff in my hand.”

10Joshua did as Moses had told him, and fought against Amalek, while Moses, Aaron, and Hur went up to the top of the hill.

11While Moses held up his hand, Israel prevailed, but whenever he put his hand down, Amalek prevailed.

12When Moses’s hands grew heavy, they took a stone and put it under him, and he sat down on it. Then Aaron and Hur supported his hands, one on one side and one on the other so that his hands remained steady until the sun went down.

13So Joshua defeated Amalek and his army with the sword.