The people of Israel sent messengers to speak to Sihon. He was the king of the Amorites. The messengers said to him,
References for Numbers 21:21
"Let us pass through your country. We won't go off the road into any field or vineyard. We won't drink water from any well. We'll travel along the king's highway. We'll just go straight through your territory."
But Sihon wouldn't let Israel pass through his territory. He gathered his whole army together. Then he marched out into the desert against Israel. When he reached Jahaz, he fought against Israel.
But Israel put him to death with their swords. They took over his land. They took everything from the Arnon River to the Jabbok River. But they didn't take over any of the land of the Ammonites. That's because the Ammonites had built strong forts along their border.
The people of Israel captured all of the cities of the Amorites. Then they settled down in them. They captured the city of Heshbon. They also captured all of the settlements that were around it.
Sihon, the king of the Amorites, ruled in Heshbon. He had fought against an earlier king of Moab. Sihon had taken from him all of his land all the way to the Arnon River.
That's why the poets say, "Come to Heshbon. Let it be built again. Let Sihon's city be made as good as new.
"Fire went out from Heshbon. A blaze went out from the city of Sihon. It burned up Ar in Moab. It burned up the citizens who lived on Arnon's hills.
Moab, how terrible it is for you! People of Chemosh, you are destroyed! Chemosh has deserted his sons and daughters. His sons have run away from the battle. His daughters have become prisoners. He has handed all of them over to Sihon, the king of the Amorites.
"But we have taken them over. Heshbon is destroyed all the way to Dibon. We have destroyed them as far as Nophah. Nophah goes all the way to Medeba."
So Israel settled in the land of the Amorites.
Moses sent spies to the city of Jazer. The people of Israel captured the settlements that were around it. They drove out the Amorites who were there.
Then they turned and went up along the road toward Bashan. Og was the king of Bashan. He and his whole army marched out. They went to fight against Israel at Edrei.
The LORD said to Moses, "Do not be afraid of Og. I have handed him over to you. I have given you his whole army. I have also given you his land. Do to him what you did to Sihon, the king of the Amorites. He ruled in Heshbon."
So the people of Israel struck Og down. They struck his sons down. And they wiped out his whole army. They didn't leave anyone alive. They took over his land for themselves.