Leuco says one thing, but Leuco's ass carries another

Explanation

said of those whose words do not agree with their deeds. Leuco was a certain farmer who put skins of honey into baskets and conveyed them to Athens. He had also put barley into the baskets, so that he should pay only the small toll for barley. But when his ass fell, the toll-collectors, wishing to help, discovered it was honey, and carried it off as untaxed contraband.