Reference for Bava Batra 178:10
אמר רב יהודה אמר רב אסור לאדם שישהה מדה חסרה או יתרה בתוך ביתו ואפילו היא עביט של מימי רגלים אמר רב פפא לא אמרן אלא באתרא דלא חתימי אבל באתרא דחתימי אי לא חזי חתימה לא שקיל ובאתרא דלא חתימי נמי לא אמרן אלא דלא מהנדסי אבל מהנדסי לית לן בה
in his house a measure [which is either] smaller or larger [than the nominal capacity] even if [it is used as a] urine tub. R. Papa said: This applies only in [the case of] a place where [measures] are not [officially] marked,<span class="x" onmousemove="('comment',' By the seal of the recognised authority. ');"><sup>31</sup></span> but where they are [officially] marked [they may be used; for] if [the buyer] sees no mark he does not accept [them] — And even where they are not marked, this has been said only in the case where they are not supervised,<span class="x" onmousemove="('comment',' By duly appointed officers, [H] Others, 'marked by means of incisions'. ');"><sup>32</sup></span> but if they are supervised<span class="x" onmousemove="('comment',' By duly appointed officers, [H] Others, 'marked by means of incisions'. ');"><sup>32</sup></span> it does not matter. But this is not [right]; for [the buyer] may sometimes happen [to call] at twilight<span class="x" onmousemove="('comment',' When everyone is in a hurry. ');"><sup>33</sup></span>