The Horites also lived in Seir formerly, but the people of Esau dispossessed them and destroyed them from before them and settled in their place, as Israel did to the land of their possession, which the LORD gave to them.)
It is observable here that Moses, speaking of the Edomites (Deu 2:8), calls them, "our brethren, the children of Esau." Though they had been unkind to Israel, in refusing them a peaceable passage through their country, yet he calls them brethren.
Commenting on Deuteronomy 2:8-23
The Horims also dwelt in Seir before time,.... Which is the name of a mount, and so of the country, from it; so called from Seir the Horite, who dwelt in it before it was possessed by Esau and his sons; but who the Horim or Horites were, from whence they had their name, is difficult to say; they were as early as the times of Chedorlaomer, Gen 14:6.
Deu 2:11-12 To confirm the fact that the Moabites and also the Edomites had received from God the land which they inhabited as a possession, Moses interpolates into the words of Jehovah certain ethnographical notices concerning the earlier inhabitants of these lands, from which it is obvious that Edom and Moab had not destroyed them by their own power, but that Jehovah had destroyed them...
Commenting on Deuteronomy 2:11-12