Exodus 17:12
King James Version
“But Moses’ hands heavy; and they took a stone, and put 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.”
Context
9And Moses said unto Joshua, Choose us out men, and go out, fight with Amalek: to morrow I will stand on the top of the hill with the rod of God in mine hand.
10So Joshua did as Moses had said to him, and fought with Amalek: and Moses, Aaron, and Hur went up to the top of the hill.
11And it came to pass, when Moses held up his hand, that Israel prevailed: and when he let down his hand, Amalek prevailed.
12But Moses’ hands heavy; and they took a stone, and put 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.
13And Joshua discomfited Amalek and his people with the edge of the sword.
14And the LORD said unto Moses, Write this a memorial in a book, and rehearse in the ears of Joshua: for I will utterly put out the remembrance of Amalek from under heaven.
15And Moses built an altar, and called the name of it Jehovah-nissi: