וַיַּ֖עַשׂ אֶת־בֵּ֣ית בָּמ֑וֹת וַיַּ֤עַשׂ כֹּֽהֲנִים֙ מִקְצ֣וֹת הָעָ֔ם אֲשֶׁ֥ר לֹֽא־הָי֖וּ מִבְּנֵ֥י לֵוִֽי׃
And he made houses of high places, and made priests from among all the people, that were not of the sons of Levi.
Read midrashic interpretation of I Kings 12:31: and classical rabbinic exegesis.