Numbers 21:23-33

23 Sihon wouldn't let Israel pass through his territory. Sihon gathered all his troops and came out into the desert to attack Israel. When Sihon's troops came to Jahaz, they fought against Israel.
24 But Israel defeated them in battle and took possession of their land from the Arnon Valley to the Jabbok River. [They stopped at] the border of the Ammon because it was fortified.
25 Israel took all those Amorite cities, including Heshbon and all its villages, and lived in them.
26 Heshbon was the city of King Sihon of the Amorites. He had fought the former king of Moab and had taken all his land up to the Arnon Valley.
27 This is why the poets say: "Come to Heshbon! Rebuild it! Restore Sihon's city!
28 Fire came out of Heshbon, flames from Sihon's city. They destroyed Ar of Moab, the rulers of Arnon's worship sites.
29 How horrible it is for you, Moab! You are destroyed, you people of the god Chemosh. Chemosh let his sons become refugees and he let his daughters become prisoners of King Sihon of the Amorites.
30 But we shot the Amorites full of arrows. From Heshbon to Dibon they all died. We destroyed everyone and everything between Nophah and Medeba."
31 So Israel settled in the land of the Amorites.
32 After Moses sent spies to Jazer, the Israelites captured its cities and villages and forced out the Amorites who were there.
33 Then they turned and followed the road that goes to Bashan. King Og of Bashan and all his troops came out to fight the Israelites at Edrei.