Then Amalek came and fought with Israel at Rephidim. So Moses said to Joshua, "Choose for us men, and go out and fight with Amalek. Tomorrow I will stand on the top of the hill with the staff of God in my hand." So Joshua did as Moses told him, and fought with Amalek, while Moses, Aaron, and Hur went up to the top of the hill. Whenever Moses held up his hand, Israel prevailed, and whenever he lowered his hand, Amalek prevailed. But Moses' hands grew weary, so they took a stone and put it under him, and he sat on it, while Aaron and Hur held up his hands, one on one side, and the other on the other side. So his hands were steady until the going down of the sun. And Joshua overwhelmed Amalek and his people with the sword. Then the LORD said to Moses, "Write this as a memorial in a book and recite it in the ears of Joshua, that I will utterly blot out the memory of Amalek from under heaven." And Moses built an altar and called the name of it, The LORD Is My Banner, saying, "A hand upon the throne of the LORD! The LORD will have war with Amalek from generation to generation."
Exodus 17:8-16
In the work of the gospel the battle must be fought on these two levels also. There is the level of the preaching and the hearing of the Word, but there is also the raising of the standard, so to speak, claiming the mighty advocacy of the Son at God's right hand against the powers of darkness that blinds the minds of them that believe not. If the rod signifies anything so far as Moses is concerned, it must surely represent all his being's ransomed powers taken up at the behest of God and used in His Name. The power of a consecrated life in the place of prayer is truly incalculable; it can bring water out of the rock, turn stones into bread, and banish the powers of darkness from the lives of men. But even the mighty Moses' hands grew weak and faint; it is a costly business to win battles for God in prayer, and natural weariness takes its inevitable toll. This is precisely where fellowship comes in. Moses needed Aaron and Hur to hold up his weary hands, so as to keep them steady till the going down of the sun. Here is a deep and challenging lesson for those who are not called to be leaders of God's work but rather to be the support and strength of those who are, in the deep inner fellowship and harmony that those know who have shared and assumed the discipline of the Cross.