You shall utterly destroy all the places where the nations that you are dispossessing served their gods: on the high mountains and on the hills and under every leafy tree.
English: “Their gods on the mountains” — Mountains and hills that are worshipped are permitted for benefit, for the verse says “where the nations served their gods on the mountains” — and not that the mountains themselves are their gods.
On the daf / in context: Attached natural features (mountains, hills) remain permitted because they are regarded as the common property of the world and cannot be rendered forbidden by idolatrous designation in the same way as movable objects.
Type of Learning
Derash on the verse (Sifrei / Bavli) — distinguishing the idol from the natural location.
What Is Learned
Mountains and hills that were used for idolatry remain permitted for ordinary use and benefit.