Exodus 17:10-12

New Revised Standard Version Updated Edition

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. ¹² But Moses’s hands grew heavy, so they took a stone and put it under him, and he sat on it. Aaron and Hur held up his hands, one on either side, so his hands were steady until the sun set.