Ketubot 99B

שהקטנית בסלע, וקטנית בפרוטה. שמע מינה.

As, whether he bought legumes for a sela or whether he bought legumes for a peruta, the price would have been the same even if he bought in bulk. The Talmud concludes: Learn from here that this is the proper interpretation of the Mishnah.

היכי דמי? אילימא באתרא דמזבני בשומא, היכא דיהיב ליה סלע ⁠— מוזלי גביה טפי!

The Talmud asks about the sale of legumes: What are the circumstances where the price stays the same even if one bought in bulk? If we say that it occurs in a locale where they sell legumes by appraisal of an article’s value, then when he gives the merchant a sela as payment, the seller reduces the price for him more than if he had bought less. In such a place the buyer profits, and it is clear that even legumes do not have a fixed price.

אמר רב פפא: באתרא דכיילי בכני, דאמר ליה: ״כנא כנא בפרוטה״.

Rav Pappa said: It is referring to a locale where one measures with vessels and to a case where the merchant said to him: Fill each vessel for a peruta. The buyer then receives the product in accordance to how much he pays, and does not pay less if he buys in bulk.

תא שמע: היתה כתובתה ארבע מאות זוז, מכרה לזה במנה ולזה במנה ולאחרון יפה מנה ודינר במנה ⁠— של אחרון בטל, ושל כולן מכרן קיים.

The Talmud suggests: Come and hear a proof from the Mishnah: If her marriage contract was worth 400 dinars, and she sold property to this one for 100 dinars, and she sold property to that one for 100 dinars, and again to a third one, and she sold property to the last one worth 100 dinars and a dinar for only 100 dinars, the sale of the last property is void, and all of the others, their sale is valid, as they were sold for the correct price. Here, the widow was appointed as an agent to sell property worth 400 dinars, and she initially sold property worth only 100 dinars, and nevertheless the sale is valid. The Mishnah does not say that she disregarded the orphan’s instructions and the sale is void.