Here, as in 2 Kings 23:16, Josiah may have regarded himself as bound to act as he did (marginal reference "b"). Excepting on account of the prophecy, he would scarcely have slain the priests upon the altars.

Slew all the priests - The lives of these, as corrupters of the people, were forfeited to the law.

And he slew all the priests of the high places that were there,.... The idolatrous priests who sacrificed to Baal, and other Heathen deities; for as for others that burnt incense in high places, yet to the true God, those he spared, though they were not suffered to officiate at the altar of God: the others he slew

upon the altars; where they sacrificed:

and burnt men's bones upon them: the bones of the priests, and worshippers of idols, as he had done at Bethel:

and returned to Jerusalem; after he had gone through the land, both of Judah and Israel, and abolished idolatrous worship everywhere.

And he slew all the priests of the high places that were there upon the altars, and burned men's bones upon them, and returned to Jerusalem.

23:20 The priests - By this relation it appears, that after the departure of the king of Assyria, divers of the Israelites who had retired to other parts, and kept themselves out of the conqueror's hands, returned together with their priests to their own land, and to their old trade, worshipping idols; to whom, peradventure, they ascribed this their deliverance from that judgment which Jehovah had brought upon them. And burnt - According to that famous prophecy, 1Kings 13:1,2.

slew: or, sacrificed

23:15-24 Josiah's zeal extended to the cities of Israel within his reach. He carefully preserved the sepulchre of that man of God, who came from Judah to foretell the throwing down of Jeroboam's altar. When they had cleared the country of the old leaven of idolatry, then they applied themselves to the keeping of the feast. There was not holden such a passover in any of the foregoing reigns. The revival of a long-neglected ordinance, filled them with holy joy; and God recompensed their zeal in destroying idolatry with uncommon tokens of his presence and favour. We have reason to think that during the remainder of Josiah's reign, religion flourished.