Matthew Poole and continuators on Numbers 32:38

38 And Nebo , and Baal-meon, ( their names being changed ) and Shibmah: and gave other names unto the cities which they builded.

Of which city see Deut. 34. 1. Ier. 48. 1.

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, Exod. 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, Ios. 13. 17, 20▪

Marginal references: See Verse 3. Josh. 23. 7.; Heb. they called by names the names of the cities.