The Horites used to live in Seir before the descendants of Esau dispossessed them, exterminated them, and settled there instead, just as Israel will do in the land of its possession, which the LORD gave them.)

This is what he did for the descendants of Esau who live in Seir, when he destroyed the Horites before them. So they dispossessed them and settled there in their place, where they live to this day.