“Seest thou a man diligent in his business, he shall stand before kings” (Prov. xxii.29). “He who doeth his own business defileth not his fingers” (Fielding’s Proverbs.) Let every tubstand on its own bottom. Never meddle with what does not concern you.
“Bon homme, garde la vache. Chacun son métier, et les vaches son bien gardées. Chacun à ses affaires.”