Numbers 21:30 (KJV)

And Israel took all these cities: and Israel dwelt in all the cities of the Amorites, in Heshbon, and in all the villages thereof.

For Heshbon was the city of Sihon the king of the Amorites, who had fought against the former king of Moab, and taken all his land out of his hand, even unto Arnon.

Wherefore they that speak in proverbs say, Come into Heshbon, let the city of Sihon be built and prepared:

For there is a fire gone out of Heshbon, a flame from the city of Sihon: it hath consumed Ar of Moab, and the lords of the high places of Arnon.

Woe to thee, Moab! thou art undone, O people of Chemosh: he hath given his sons that escaped, and his daughters, into captivity unto Sihon king of the Amorites.

Thus Israel dwelt in the land of the Amorites.

And Moses sent to spy out Jaazer, and they took the villages thereof, and drove out the Amorites that were there.

And they turned and went up by the way of Bashan: and Og the king of Bashan went out against them, he, and all his people, to the battle at Edrei.

And the LORD said unto Moses, Fear him not: for I have delivered him into thy hand, and all his people, and his land; and thou shalt do to him as thou didst unto Sihon king of the Amorites, which dwelt at Heshbon.

So they smote him, and his sons, and all his people, until there was none left him alive: and they possessed his land.