אַל־תַּלְשֵׁ֣ן עֶ֭בֶד אֶל־אדנו [אֲדֹנָ֑יו] פֶּֽן־יְקַלֶּלְךָ֥ וְאָשָֽׁמְתָּ׃
Slander not a servant unto his master, Lest he curse thee, and thou be found guilty.
Read kabbalistic (mystical) interpretation of Proverbs 30:10: and classical mystical sources.