15 Next, he took care of the altar at the shrine in Bethel that Jeroboam son of Nebat had built - the same Jeroboam who had led Israel into a life of sin. He tore apart the altar, burned down the shrine leaving it in ashes, and then lit fire to the phallic Asherah-pole. 16 As Josiah looked over the scene, he noticed the tombs on the hillside. He ordered the bones removed from the tombs and had them cremated on the ruined altars, desacralizing the evil altars. This was a fulfillment of the word of God spoken by the Holy Man years before when Jeroboam had stood by the altar at the sacred convocation. 17 Then the king said, "And that memorial stone - whose is that?" The men from the city said, "That's the grave of the Holy Man who spoke the message against the altar at Bethel that you have just fulfilled." 18 Josiah said, "Don't trouble his bones." So they left his bones undisturbed, along with the bones of the prophet from Samaria.
Matthew Henry's Commentary on 2 Kings 23:15-18
Commentary on 2 Kings 23:15-24
(Read 2 Kings 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.