The crushing of those concealed in the caves of the mountain at Arnon was only the beginning of the miracles God wrought for Israel during their conquest of the land. It was at Arnon, too, that Sihon, the king of the Amorites, and his people who, hardly a month after Aaron's death, rushed upon Israel, were completely destroyed by them.  This Amorite king, and likewise Og, the king of Basham, were sons of Ahiah, whose father Shemhazai was one of the fallen angels.  In accordance with his celestial origin Sihon was a giant who none could withstand, for he was of enormous stature, taller than any tower in all the world, his thigh-bone alone measuring eighteen cubits, according to the big cubit of that time.  In spite of his huge size he was also fleet of foot, wherefore he was called Sihon, "foal," to indicate the celerity with which he moved, for his true name was Arad. 
Moses was sorely afraid of waging war against this giant, but God put Sihon's and Og's guardian angels in chains, and then said to Moses: "Behold, I have begun to deliver up Sihon and his land before thee: begin to possess, that thou mayest inherit his land." For indeed after the angels of Sihon and his people had fallen, Moses had nothing more to fear, for his enemies were thus delivered into his hands.  God assured Moses that "He would begin to put the dread of him and the fear of him upon the peoples that are under the whole heaven," by bidding the sun to stand still during his war against Sihon, that all the world might see that God battled for Moses. 
Moses now asked if he might before waging war send ambassadors to Sihon to request him to permit Israel to pass through the land. God replied: "How now! I commanded thee, 'Rise up, contend with him in battle, begin to possess his land!' and thou wantest to send him messengers of peace?" Moses, however, replied: "I desire only to follow Thy example when Thou didst wish to lead Israel out of Egypt, and yet didst send me to Pharaoh with the message to let Israel, Thy people, pass out, even though Thou couldst have consumed all of Egypt with one flash of lightning. When Thou didst reveal the Torah, too, Thou didst offer it to the heathen nations for acceptance before giving it to Israel." God saw the justice of Moses' words, and commanded him never in the future to declare war upon a city before previously urging the people to surrender in peace. 
Moses hereupon sent a missive to Sihon in which he requested him to permit Israel to pass through the land, promising him that he would see to it that the people should go along by the king's highway, so that he need have no cause to fear any deeds of violence upon married women, or seductions of girls.  "We shall even," continued Moses, "pay for the water that is otherwise given freely, and likewise  buy food-stuffs from thee at good prices."  This letter to Sihon contained at its close, notwithstanding, the communication that the Israelites would bring war upon Sihon in case he did not permit them to pass through. Moses' assumption, however, that Sihon should permit Israel to pass through sounded in Sihon's ears like a summons to the keeper of a vineyard to permit one to harvest it. Sihon's answer therefore was as follows: "I and my brother Og receive tribute from all the other Canaanite kings to keep off their enemies from access to the land, and now you ask me to give you free access to Canaan!"
War between Sihon and Moses ensued, and ended in a brilliant victory for Israel.  Sihon and his son, who equaled him in heroic strength, found their death in this fray.  God had so brought it to pass that Israel had no need of laboriously waging war upon one city after another in Sihon's land, He had brought all the hosts of this Amorite king together into Heshbon. When this city therefore and the hosts within it were destroyed, all the rest of Sihon's land lay open before them. Israel's victory was all the more marvelous, because Heshbon was an exceptionally well fortified city, so that, had gnats been its inhabitants, it could not have been captured by mortal means, much less so when manned by the hero Sihon and his heroic warriors.  This victory was made possible only by the fact that God visited them with convulsions so terrible that they rolled up and writhed in pain, unable to stand in the battle lines, so that Israel could cut them down while they were half dead from convulsive pains.  God also drew masks over their faces, so that they could not see plainly, and taking one another for Israelites, slew their own people. 
With the fall of Heshbon Israel came into possession of all the land of Sihon, with the exception of Jazer, and Moses therefore sent spies to that city. The men whom he sent there, Caleb and Phinehas, were not only capable warriors, but also pious men. They said: "Moses once sent spies who brought great misfortune upon all their generations, we will attack this city, trusting in God, and we are sure we shall not perish, because Moses has prayed for our welfare." They thereupon attacked Jazer, conquered it, and when upon the day after Moses had sent them out they returned to him, they informed him that they had conquered Jazer and slain its inhabitants.