To glorify the victory over Amalek, Moses built an altar, which God called "My Miracle," for the miracle God wrought against Amalek in the war of Israel was, as it were, a miracle for God. For so long as the Israelites dwell in sorrow, God feels with them, and a joy for Israel is a joy for God, hence, too, the miraculous victory over Israel's foe was a victory for God.
"Smite a scorner, and the simple will beware." The destruction of Amalek brought Jethro to his senses. Jethro was originally in the same plot with Amalek, both having incited Pharaoh against Israel, but when he saw that Amalek lost this world and the other, he repented of his sinful ways, saying: "There is nothing left to me but to go over to the God of Israel"; and although he dwelt in the greatest wealth and honor, he determined to set out for the desert, to Moses and his God. Arrived at the camp of Israel, he could not enter it, for it was enveloped by a cloud that none could pierce, hence he wrote a letter to Moses and shot it off with an arrow, so that it fell into the camp. The letter read: "I adjure thee, by thy two sons and by thy God, to come to meet me and receive me kindly. If thou wilt not do if for my sake, do it for thy wife's sake; and if thou wilt not do it for her sake, do it for thy sons' sake." For Jethro brought with him his daughter Zipporah, from whom Moses had been divorced, as well as her two sons, her only children, for after her separation from Moses, she had wed no other man.