they would say in Sura: Give me that cut of meat called a tarta or half a tarta, without naming a price. In Neresh they would say in reference to those same portions: A part or half a part. In Pumbedita they would say: An uzya or half an uzya. In Nehar Pekod and in Mata Meḥasya they would say: Give me 1/4th or half 1/4th, thereby establishing the size of the portion without mentioning its price.
מתני׳ אומר אדם לחברו: מלא לי כלי זה, אבל לא במדה. רבי יהודה אומר: אם היה כלי של מדה — לא ימלאנו. מעשה באבא שאול בן בטנית, שהיה ממלא מדותיו מערב יום טוב ונותנן ללקוחות ביום טוב.
Mishnah: One person may say to another on a Festival: Fill this vessel for me, and I will return its contents or reimburse you after the Festival, but he may not ask him to fill the vessel in a particular measure. R' Yehuda says: If it was a measuring utensil, he may not fill it. There was an incident involving Abba Shaul ben Botnit, a Sage who was also a grocer, who would fill his measures on the eve of a Festival and give them to his customers on the Festival. In this way he would know exactly how much he had given each person, without conducting any measurements on the Festival itself.
אבא שאול אומר: אף במועד עושה כן, מפני ברורי המדות. וחכמים אומרים: אף בחול עושה כן, מפני מצוי המדות.
Abba Shaul, a Sage distinct from Abba Shaul ben Botnit, says: He would do this even on the intermediate days of a Festival because of the clarity of the measures, i.e., in order to clarify precisely how much must be given to each customer, since the measurement is more precise once the foam of the liquid being measured has subsided. And the Rabbis say: Even on a weekday it is proper to do so, because of the draining of the measures. This method allows all the liquid to drain fully out of the seller’s measuring utensil so that the amount is exact.