Charles Ellicott Commentary 2 Chronicles 31:1

"Now when all this was finished, all Israel that were present went out to the cities of Judah, and brake in pieces the pillars, and hewed down the Asherim, and brake down the high places and the altars out of all Judah and Benjamin, in Ephraim also and Manasseh, until they had destroyed them all. Then all the children of Israel returned, every man to his possession, into their own cities." — 2 Chronicles 31:1 (ASV)

Destruction of the images and high places in both kingdoms. (Compare to 2 Kings 18:4.)

Now when all this was finished. — And when they had finished all this —that is, the business of the Passover.

All Israel that were present went out. —Their iconoclastic zeal had been thoroughly roused by the festival in which they had just taken part.

The images. — Maççebôth, “pillars.” (See Hosea 3:4, and 2 Chronicles 14:2.)

The groves. — The Ashçrîm. The sacred trunks, emblematic of physical fertility. (Compare to Hosea 4:13.)

In Ephraim also and Manasseh. —That is, in the territory of the northern kingdom, which was at this time in the last stage of political weakness, and rapidly drifting towards final ruin. The band of Jewish and Israelite zealots would not, therefore, be likely to encounter any serious opposition.

Until they had utterly destroyed. —‘Adlĕkallçh (2 Chronicles 24:10). Literally, so far as to finishing.