Numbers 32:38

Nebo; of which city see Deuteronomy 34:1 Jeremiah 48:1. Their names being changed; either because conquerors of places use to do so; or because the names of other gods (which Nebo and Baal-meon unquestionably were) were not to be mentioned, Exodus 23:13, especially at the first settling of the Israelites there, that the very remembrance of the idols might be blotted out, and so the temptation to idolatry removed, though afterwards, when that danger was over, they were called by their old names again, Joshua 13:17,20.