וַיַּֽעַבְד֖וּ הַגִּלֻּלִ֑ים אֲשֶׁ֨ר אָמַ֤ר יְהוָה֙ לָהֶ֔ם לֹ֥א תַעֲשׂ֖וּ אֶת־הַדָּבָ֥ר הַזֶּֽה׃
and they served idols, whereof the LORD had said unto them: ‘Ye shall not do this thing’;
Read halakhic rulings (Jewish law) on II Kings 17:12: and classical halakhic sources.