Moses formed a cross with his body by lifting up his arms on both sides to parallel the ground when Israel was fighting the Amelkites in the desert. When Moses got tired, two Israelites held up his arms on either side to continue forming the cross. This foreshadowed the victory of the Messiah (Jesus Christ) Who would give mankind victory over their enemies; namely the devil who is now bound and cannot deceive mankind, assuming they know the Word of God.
10 So 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.
11 And it came to pass, when Moses held up his hand, that Israel prevailed: and when he let down his hand, Amalek prevailed.
12 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.
13 And Joshua discomfited Amalek and his people with the edge of the sword.