[IDEM libro IIII de officio proconsulis. ] §1.3.34.prCum de consuetudine ciuitatis uel prouinciae confidere quis uidetur, primum quidem illud explorandum arbitror, an etiam contradicto aliquando iudicio consuetudo firmata sit.
[THE SAME, On the Office of Proconsul, book 4] When someone appears to rely on a custom of a city or a province, I think that this must first of all be investigated: whether the custom has been confirmed even when on some occasion it was contested in court.