After enduring the complaints of the children of Israel, God still gave them victory over the Amalekites when they were attacked in the wilderness. He did so in such a manner as to remove any doubt about Who had given them the victory.
Ex. 17:10-16 “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. And it came to pass, when Moses held up his hand, that Israel prevailed: and when he let down his hand, Amalek prevailed. 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. And Joshua discomfited Amalek and his people with the edge of the sword. And the LORD said unto Moses, Write this for a memorial in a book, and rehearse it in the ears of Joshua: for I will utterly put out the remembrance of Amalek from under heaven. And Moses built an altar, and called the name of it Jehovahnissi: For he said, Because the LORD hath sworn that the LORD will have war with Amalek from generation to generation.”
LESSON - During this period when invading armies would attack in battle, they would fly banners representing the country and king for which they were fighting. God had chosen the rod of Aaron through which He had already performed many miracles to serve as His banner. Just like in any other warfare, when the banner remained aloft the armies of Israel were victorious. When the victory was complete, Moses commemorated the victory by building an altar and naming it Jehovahnissi which means “the banner of the Lord.” It was to serve as a reminder to God’s people that if they would follow the Lord, they would always be victorious. Today, most of the battles that we will fight in our lifetime are spiritual, not physical. Therefore, the weapons of our warfare must also be spiritual. If we will lift high the banner of the Lord in our hearts and choose to follow Him, we will also experience victory in our lives. 2 Cor. 10:3-4 “For though we walk in the flesh, we do not war after the flesh: (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds;)”