Jamieson, Fausset and Brown on 2 Chronicles 30:14

14. they arose and took away the altars that were in Jerusalem--As a necessary preparation for the right observance of the approaching solemnity, the removal of the altars, which Ahaz had erected in the city, was resolved upon (2Ch 28:24); for, as the people of God, the Hebrews were bound to extirpate all traces of idolatry; and it was a happy sign and pledge of the influence of the Spirit pervading the minds of the people when they voluntarily undertook this important preliminary work.