מלכים ב, פרק כ״ג, פסוק י״ד

King Josiah led a decisive campaign to completely uproot idolatry, an effort that expanded beyond his own borders into the areas north of the Kingdom of Judah [ביאור שטיינזלץ]. Driven to eliminate all symbols of foreign worship, he targeted the sacred pillars and trees. Because these objects were strictly forbidden from being repurposed for the worship of God, they had to be entirely destroyed. He did not simply render the sites impure but physically broke and crushed the statues until they were completely ruined [מלבי״ם].

After tearing down the idols, the king took extreme measures to ensure the locations remained permanently defiled. He filled the exact spots where the monuments once stood with human bones [רלב״ג, ביאור שטיינזלץ]. The primary approach among commentators is that these were not random remains. Instead, they were the bones of the actual idol worshippers, dug up directly from their graves. Placing these specific remains where the sacred trees and pillars used to be served as a powerful act of disgrace. Finally, to complete the eradication, the bones were burned right there on the site [רד״ק].