Deuteronomy 2:20-24

(It is also regarded as the land of the Rephaim, because the Rephaim previously lived in it, but the Ammonites call them Zamzummin,

a people as great, numerous, and tall as the Anakim; but the Lord destroyed them before them. And they dispossessed them and settled in their place,

just as He did for the sons of Esau, who live in Seir, when He destroyed the Horites from before them; they dispossessed them and settled in their place, where they remain even to this day.

And as for the Avvim, who lived in villages as far as Gaza, the Caphtorim, who came from Caphtor, destroyed them and lived in their place.)

‘Arise, set out, and pass through the Valley of Arnon. Look! I have handed over to you Sihon the Amorite, king of Heshbon, and his land; start taking possession and plunge into battle with him.