לֵ֣ךְ מִ֭נֶּגֶד לְאִ֣ישׁ כְּסִ֑יל וּבַל־יָ֝דַ֗עְתָּ שִׂפְתֵי־דָֽעַת׃
Go from the presence of a foolish man, for thou wilt not perceive the lips of knowledge.
Rashi on Proverbs
Go far away from a foolish wisdom. Do not always associate with him.
Rashi on Proverbs
or you will know lips of knowledge You will eventually not know wisdom.