כַּחֹ֤מֶץ ׀ לַשִּׁנַּ֗יִם וְכֶעָשָׁ֥ן לָעֵינָ֑יִם כֵּ֥ן הֶ֝עָצֵ֗ל לְשֹׁלְחָֽיו׃
As vinegar to the teeth, and as smoke to the eyes, So is the sluggard to them that send him.
Read kabbalistic (mystical) interpretation of Proverbs 10:26: and classical mystical sources.