They arose and took away the altars, &c. As soon as they came to Jerusalem, they began to show their zeal against idolatry, by throwing down the altars that Ahaz had erected in high places, either for sacrifice or burning incense, which were very many, (2 Chronicles 28:24,) stamping them to powder, and then casting them into the brook Kidron. Thus, before they kept the feast, they purged out the old leaven.
Related Commentaries of 2 Chronicles 30:14
2 Chronicles 30:14
14 And they arose and took away the altars that were in Jerusalem, and all the altars for incense took they away, and cast them into the brook Kidron.