וְאַתֶּם֙ סַרְתֶּ֣ם מִן־הַדֶּ֔רֶךְ הִכְשַׁלְתֶּ֥ם רַבִּ֖ים בַּתּוֹרָ֑ה שִֽׁחַתֶּם֙ בְּרִ֣ית הַלֵּוִ֔י אָמַ֖ר יְהוָ֥ה צְבָאֽוֹת׃
But ye are turned aside out of the way; Ye have caused many to stumble in the law; Ye have corrupted the covenant of Levi, Saith the LORD of hosts.
Read halakhic rulings (Jewish law) on Malachi 2:8: and classical halakhic sources.