עִקֶּשׁ־לֵ֭ב לֹ֣א יִמְצָא־ט֑וֹב וְנֶהְפָּ֥ךְ בִּ֝לְשׁוֹנ֗וֹ יִפּ֥וֹל בְּרָעָֽה׃
He that hath a forward heart findeth no good; And he that hath a perverse tongue falleth into evil.
Read kabbalistic (mystical) interpretation of Proverbs 17:20: and classical mystical sources.