Siman - Eruvin Daf 83

  • Different measurements for a se’ah

The Mishnah on Daf 82b discussed the quantity of bread required to make an eruv, which lead to the Gemara analyzing the specific measurements. A Baraisa on this Daf teaches, סאה ירושלמית יתירה על מדבריות שתות - The Yerushalmi se’ah is larger than the se’ah in the midbar by a sixth, which Rashi explains to mean what we call a fifth, ושל ציפורית יתירה על ירושלמית שתות – and the Tzipori se’ah is larger than the Yerushalmi se’ah by a sixth, which we would refer to as a fifth.

The Midbar se’ah was in use when the Torah was given and had a volume of 144 kibeitzim.

The Yerushalmi se’ah was introduced during the time of Bayis Rishon and had a volume of 173 kibeitzim.

The Tzipori se’ah was adopted when the Sanhedrin was located in Tzipori which occurred during Rebbe’s leadership. It was 207 kibeitzim.

  • The amount of dough to be obligated to separate challah

It was taught in a Baraisa regarding the mitzvah of challah, that the passuk says ראשית ערסתכם – The first of your doughs, “your doughs” implies that the dough from which one must separate challah is “your dough” that you had in the Midbar. How much was the dough in the Midbar, meaning the daily portion of mann? והעומר עשרית האיפה הוא – and the Omer is one tenth of an Ephah. The ephah was equal to three se’ah, so that the omer according to the size of the dough in the Midbar was 3/10 of a se’ah.

The Baraisa concludes, האוכל במדה זו הרי זה בריא ומבורך – One who eats as much as this measure, referring to the minimum quantity specified for challah, is healthy and blessed. יתר על כן רעבתן – If he eats more he is considered a glutton. פחות מכאן מקולקל במעיו – If he eats less than this, his innards are defective.

  • Lowering vs. throwing

The next Mishnah introduces the principle that the use of an area is assigned to those for whom it is easier to use. The Gemara lists six cases of areas accessible to two chatzeiros who have each made a separate eruv. There is a machlokes between Rav and Shmuel in a case of, לזה בשלשול ולזה בזריקה – a given area which is only accessible to the residents in one chatzeir by lowering objects to that area, and only accessible to the residents in the other chatzeir by throwing objects to the area. Rav holds they are both forbidden since the degree of difficulty in using the area is equal. Shmuel holds that the residents who can lower into the area are permitted to use it because, תשמישו בנחת - its use is with ease. Lowering down requires less effort than throwing up.

The Gemara on the next amud attempts to determine if the halachah is according to Rav or Shmuel but fails to come to a resolution.