Ecclesiastes 10:1 Kabbalah

זְב֣וּבֵי מָ֔וֶת יַבְאִ֥ישׁ יַבִּ֖יעַ שֶׁ֣מֶן רוֹקֵ֑חַ יָקָ֛ר מֵחָכְמָ֥ה מִכָּב֖וֹד סִכְל֥וּת מְעָֽט׃

Dead flies make the ointment of the perfumer fetid and putrid; So doth a little folly outweigh wisdom and honour.

Read kabbalistic (mystical) interpretation of Ecclesiastes 10:1: and classical mystical sources.