וַיַּ֥עַשׂ הָרַ֖ע בְּעֵינֵ֣י יְהוָ֑ה כְּתֽוֹעֲבֹת֙ הַגּוֹיִ֔ם אֲשֶׁר֙ הוֹרִ֣ישׁ יְהוָ֔ה מִפְּנֵ֖י בְּנֵ֥י יִשְׂרָאֵֽל׃
And he did that which was evil in the sight of the LORD, after the abominations of the nations, whom the LORD cast out before the children of Israel.
Read midrashic interpretation of II Kings 21:2: and classical rabbinic exegesis.