וְעוּכְלָא וְכַמָּה הִיא עוּכְלָא אֶחָד מֵחֲמִשָּׁה בִּרְבִיעַ וּבְמִדַּת הַלַּח הוּא עוֹשֶׂה הִין וַחֲצִי הִין וּשְׁלִישִׁית הַהִין וּרְבִיעִית הַהִין וְלוֹג וַחֲצִי לוֹג וּרְבִיעִית וּשְׁמִינִית וְאֶחָד מִשְּׁמוֹנָה בִּשְׁמִינִית וְזֶהוּ קוּרְטוֹב and an ukla. And how much is an ukla? It is one-fifth of a quarter of a kav. And in the case of liquid measures, one may prepare a hin, which is twelve log; and a half-hin, or six log; and a third-hin, or four log; and a quarter-hin, three log; and a log; and a half-log; and a quarter-log; and an eighth-log; and an eighth of an eighth-log, and this, the last mentioned, is a kortov.
וְלֶעְבֵּיד נָמֵי קַבַּיִים אָתֵי לְאִיחַלּוֹפֵי בְּתַרְקַב אַלְמָא טָעוּ אִינָשֵׁי תִּילְתָּא אִי הָכִי קַב נָמֵי לָא לֶיעְבֵּיד דְּאָתֵי לְאִיחַלּוֹפֵי בַּחֲצִי תַּרְקַב אֶלָּא קַבַּיִים הַיְינוּ טַעְמָא דְּלָא עָבֵיד דְּאָתֵי לְאִיחַלּוֹפֵי בַּחֲצִי תַּרְקַב The Gemara asks: And let one also prepare a measure equal to two kav. The Gemara answers that this measure is not used, lest people come to mistake it for a tarkav, which is three kav. The Gemara observes: Apparently, people err by one-third of a measure. If that is so, one should also not prepare a measure equal to a kav, as people may come to mistake it for a half-tarkav, which is equal to one and one-half kav. Rather, this is the reason that one may not prepare a two-kav measure: That people might come to mistake it for a half-tarkav, which is equal to one and one-half kav.
אַלְמָא טָעֵי אִינִישׁ רִיבְעָא אִי הָכִי חֲצִי תּוֹמֶן וְעוּכְלָא לָא לֶיעְבֵּיד אָמַר רַב פָּפָּא מִדּוֹת קְטַנּוֹת בְּקִיאִי בְּהוּ אִינָשֵׁי The Gemara again suggests: Apparently, people err by one-quarter of a measure. If that is so, one should also not prepare measures of a half-tomen, which is one-sixteenth of a kav, and an ukla, which is one-twentieth of a kav. Since they differ by only one-fifth, there is a concern that people might mistake one measure for the other. Rav Pappa said: People are well-versed in small measures and can distinguish between them.
שְׁלִישִׁית הַהִין רְבִיעִית הַהִין לָא לֶיעְבֵּיד כֵּיוָן דַּהֲווֹ בַּמִּקְדָּשׁ לָא גְּזַרוּ בְּהוּ רַבָּנַן בַּמִּקְדָּשׁ נָמֵי לִיגְזוֹר כֹּהֲנִים זְרִיזִין הֵן: The Gemara continues: If people err by one-quarter of a measure, then since one may prepare a measure equal to four log, one-third of a hin, let one not prepare a measure equal to three log, one-quarter of a hin. The Gemara answers: Since these measures were used in the Temple, the Sages did not decree that they not be used. The Gemara asks: In the Temple as well, let the Sages decree that they should not be used, in case the two measures are mistaken for each other. The Gemara answers: The priests who serve in the Temple are vigilant and would not commit this error.
אָמַר שְׁמוּאֵל אֵין מוֹסִיפִין עַל הַמִּדּוֹת יוֹתֵר מִשְּׁתוּת וְלֹא עַל הַמַּטְבֵּעַ יָתֵר מִשְּׁתוּת וְהַמִּשְׂתַּכֵּר אַל יִשְׁתַּכֵּר יוֹתֵר מִשְּׁתוּת אֵין מוֹסִיפִין עַל הַמִּדּוֹת יוֹתֵר מִשְּׁתוּת מַאי טַעְמָא אִילֵּימָא מִשּׁוּם אַפְקוֹעֵי תַּרְעָא שְׁתוּת נָמֵי לָא § Shmuel says: If the residents of a certain place want to change the standard of their measures and augment them by a certain fraction, they may not increase the measures by more than one-sixth, and they may not increase the value of a coin by more than one-sixth of its previous value. And one who profits from his sales may not profit by more than one-sixth. The Gemara analyzes these statements. When Shmuel said: They may not increase the measures by more than one-sixth, what is the reason for this? If we say it is because doing so causes market prices to rise, the same concern should apply to raising the prices by one-sixth, and therefore this should also not be allowed.
אֶלָּא מִשּׁוּם אוֹנָאָה דְּלָא לֶיהֱוֵי בִּיטּוּל מִקָּח וְהָאָמַר רָבָא כׇּל דָּבָר שֶׁבְּמִדָּה וְשֶׁבְּמִשְׁקָל וְשֶׁבְּמִנְיָן אֲפִילּוּ פָּחוֹת מִכְּדֵי אוֹנָאָה חוֹזֵר Rather, you will say that the prohibition is due to concern for exploitation; and they may increase the measures only by up to one-sixth, so that there will not be nullification of the transaction, as the transaction is nullified only when the disparity is more than one-sixth of the value of the item. The Gemara raises an objection: But doesn’t Rava say: With regard to any item that is otherwise subject to the halakhot of exploitation, and it is sold by measure, or by weight, or by number, even if the disparity was less than the measure of exploitation in the transaction, the transaction is reversed. A disparity of one-sixth between the value of an item and its price constitutes exploitation only in cases where there is room for error in assessing the value of an item. In a case where the details of the item are easily quantifiable, any deviation from the designated quantity results in a nullification of the transaction.
אֶלָּא דְּלָא לֶיהֱוֵי פְּסֵידָא לְתַגָּרָא Rather, the prohibition is so that there will not be a loss suffered by the merchant, who might not realize that a new standard was issued, and sell in accordance with the old standard. Since a merchant usually enjoys a profit of one-sixth of the value of an item, if the standard is not increased by more than this amount he will not suffer a loss, as at worst he will forfeit his profit margin.
פְּסֵידָא הוּא דְּלָא לֶיהֱוֵי לֵיהּ רַוְוחָא לָא בָּעֵי זְבַן וְזַבֵּין תַּגָּרָא אִיקְּרִי This Gemara notes: This explanation is also difficult, since even if the aim is to ensure that there will not be a loss for the merchant, does he not need to earn a profit? There is a well-known adage in this regard: If you buy and sell without making any profit, will you be called a merchant? A merchant must profit from his sales; therefore, if this decree was instituted for the protection of merchants, the Sages should have ensured that they earn a profit.
אֶלָּא אָמַר רַב חִסְדָּא שְׁמוּאֵל קְרָא אַשְׁכַּח וּדְרַשׁ וְהַשֶּׁקֶל עֶשְׂרִים גֵּרָה עֶשְׂרִים שְׁקָלִים חֲמִשָּׁה וְעֶשְׂרִים שְׁקָלִים עֲשָׂרָה וַחֲמִשָּׁה שֶׁקֶל הַמָּנֶה יִהְיֶה לָכֶם Rather, Rav Ḥisda said: The prohibition is not based on logical reasoning. Instead, Shmuel found a verse and interpreted it homiletically: “And the shekel shall be twenty gera; twenty shekels, five and twenty shekels, ten, and five shekels, shall be your maneh” (Ezekiel 45:12). According to this verse, the combination of all of these numbers, sixty shekels, is equivalent to a maneh.