The ashes, being polluted and polluting, were thrown upon graves, because there no one could come into contact with them, since graves were avoided as unclean places.

He brought out the grove - He brought out the idol Asherah. See at the end of 2 Kings 21:26 (note).

Upon the graves of the children of the people - I believe this; means the burial-place of the common people.

And he brought out the grove from the house of the Lord,.... Not a real grove of trees, but a carved one, as some think; or rather the image of the grove, 2 Kings 21:7 that is, the idol Ashtoreth, or Astarte, which was set up there; so Theodoret says; some interpreters call it Astoreth, the name of Venus, whom they call Astarte: this Josiah ordered to be brought

without Jerusalem, unto the brook Kidron, and burnt it at the brook Kidron; the black brook, where the filth of the sacrifices was carried:

and stamped it small to powder; as Moses did the golden calf:

and cast the powder thereof upon the graves of the children of the people; the common people, see Jeremiah 26:23 or rather on the graves of the worshippers of idols, as it seems from 2 Chronicles 34:4 the Targum is,"on the graves of the children of Galia,''which, Kimchi says, is the name of an idol; this was done partly in contempt of the idol, groves being, according to law, impure; and partly to the reproach of the deceased, and the memory of them, for their idolatry, and to deter from it those that survived them.

The image of Asherah (האשׁרה equals הא פּסל, 2 Kings 21:3, 2 Kings 21:7), which Manasseh placed in the temple and then removed after his return from Babylon (2 Chronicles 33:15), but which Amon had replaced, Josiah ordered to be burned and ground to powder in the valley of Kidron, and the dust to be thrown upon the graves of the common people. ויּדק, from דקק, to make fine, to crush, refers to the metal covering of the image (see at Exodus 32:10). Asa had already had an idol burned in the Kidron valley (1 Kings 15:13), and Hezekiah had ordered the idolatrous abominations to be taken out of the city and carried thither (2 Chronicles 29:16); so that the valley had already been defiled. There was a burial-place there for העם בּני, i.e., the common people (cf. Jeremiah 26:23), who had no graves of their own, just as at the present day the burial-ground of the Jews there lies to the north of Kefr Silwn. Josiah ordered the ashes to be cast upon these graves, probably in order to defile them as the graves of idolaters.

And he brought out the {g} grove from the house of the LORD, without Jerusalem, unto the brook Kidron, and burned it at the brook Kidron, and stamped it small to powder, and cast the powder thereof upon the {h} graves of the children of the people.

(g) He removed the grove which idolaters for devotion had planted near the temple, contrary to the commandment of the Lord, De 16:21, or as some read, the similitude of a grove which was hung in the temple.

(h) Both in contempt of the idols and reproach of them who had worshipped them in their lives.

23:6 The people - Of that people, those idolatrous people, as it is explained, 2Chron 34:4.

Margin grove

See Scofield Note: "Dt 16:21".

6. brought out the grove-that is, Asherah, the mystic tree, placed by Manasseh in the temple [2Ki 21:5; 2Ch 33:5], removed by him after his conversion [2Ch 33:15], but replaced in the sanctuary by his wicked son Amon [2Ki 21:20, 21]. Josiah had it taken to Kidron, burnt the wood, ground the metal about it to powder, and strewed the ashes "on the graves of the children of the people." The poor were buried in a common on part of the valley of Kidron. But reference is here made to the graves "of those that had sacrificed" (2Ch 34:4).

23:4-14 What abundance of wickedness in Judah and Jerusalem! One would not have believed it possible, that in Judah, where God was known, in Israel, where his name was great, in Salem, in Zion, where his dwelling-place was, such abominations should be found. Josiah had reigned eighteen years, and had himself set the people a good example, and kept up religion according to the Divine law; yet, when he came to search for idolatry, the depth and extent were very great. Both common history, and the records of God's word, teach, that all the real godliness or goodness ever found on earth, is derived from the new-creating Spirit of Jesus Christ.