וַ֠יִּזְבַּח אֶת־כָּל־כֹּהֲנֵ֨י הַבָּמ֤וֹת אֲשֶׁר־שָׁם֙ עַל־הַֽמִּזְבְּח֔וֹת וַיִּשְׂרֹ֛ף אֶת־עַצְמ֥וֹת אָדָ֖ם עֲלֵיהֶ֑ם וַיָּ֖שָׁב יְרוּשָׁלִָֽם׃
And he slew all the priests of the high places that were there, upon the altars, and burned men’s bones upon them; and he returned to Jerusalem.
Read kabbalistic (mystical) interpretation of II Kings 23:20: and classical mystical sources.