Exodus 17:9-11

New Revised Standard Version, Anglicised

⁹ Moses said to Joshua, ‘Choose some men for us and go out; fight with Amalek. Tomorrow I will stand on the top of the hill with the staff of God in my hand.’ ¹⁰ So Joshua did as Moses told him, and fought with Amalek, while Moses, Aaron, and Hur went up to the top of the hill. ¹¹ Whenever Moses held up his hand, Israel prevailed; and whenever he lowered his hand, Amalek prevailed.