Matthew Poole and continuators on 2 Chronicles 17:13

13 And he had much business in the cities of Judah : and the men of war mighty men of valour were in Jerusalem.

Partly to repair and fortifie them, and furnish them with all necessary Provisions: and partly to purge out all the Reliques and Seeds of Idolatry and Injustice which were more secretly and subtilly managed in the Cities than in the Country, and which were first and most in the Cities, and thence spread their Infection into the Country about them. See Ier. 2. 28.