phrase/θapaˌteɾo | a tus θaˈpatos/
cobbler, keep to your last (used to criticize someone who opines about a subject without knowing it)
An anecdote attributed to Apelles; When a cobbler commented on his mistakes in painting a shoe, Apelles made the corrections that very night; the next morning the cobbler noticed the changes, and proud of his effect on the artist's work began to criticize how Apelles portrayed the leg—whereupon Apelles emerged from his hiding-place to state: Ne sutor ultra crepidam—"Let the shoemaker venture no further.". The phrase literally means "cobbler, (keep) to your shoes".