Exodus 17:12

17:12 But Moses' hands were heavy; and they took a stone, and put it under him, and he sat on it. Aaron and Hur held up his hands, the one on the one side, and the other on the other side. His hands were steady until sunset.
-World English Bible

Other Translation

17:12 But Moses' hands [were] heavy; and they took a stone, and put [it] under him, and he sat thereon; and Aaron and Hur stayed up his hands, the one on the one side, and the other on the other side; and his hands were steady until the going down of the sun.
-King James Version