Talmud - Eruvin 83b עירובין פ״ג ב׳

What is the quantity of dough from which ḥalla must be separated? The amount of “your dough.” And how much is “your dough”? This amount is left unspecified by the verse. The Gemara answers: It is as the amount of the dough of the wilderness. The Gemara again asks: And how much is the dough of the wilderness?

The Gemara responds: The Torah states that the manna, the dough of the wilderness, was “an omer a head” (Exodus 16:16). A later verse elaborates on that measure, as it is written: “And an omer is the tenth part of an eifa” (Exodus 16:36). An eifa is three se’a, which are eighteen kav or seventy-two log. An omer is one-tenth of this measure. From here, this calculation, Sages said that dough prepared from seven quarters of a kav of flour and more is obligated in ḥalla. This is equal to six quarter-kav of the Jerusalem measure, which is five quarter-kav of the Tzippori measure.

From here the Sages also said: One who eats roughly this amount each day, is healthy, as he is able to eat a proper meal; and he is also blessed, as he is not a glutton who requires more. One who eats more than this is a glutton, while one who eats less than this has damaged bowels and must see to his health.

MISHNA: If both the residents of houses that open directly into a courtyard and the residents of apartments that open onto a balcony from which stairs lead down to that courtyard forgot and did not establish an eiruv between them, anything in the courtyard that is ten handbreadths high, e.g., a mound or a post, is part of the balcony. The residents of the apartments open to the balcony may transfer objects to and from their apartments onto the mound or post. Any post or mound that is lower than this height is part of the courtyard.

A similar halakha applies to an embankment that surrounds a cistern or a rock: If the embankments that surround a cistern or rock are ten handbreadths high, they belong to the balcony; if they are lower than this, they may be used only by the inhabitants of the courtyard.

In what case are these matters, the halakha that anything higher than ten handbreadths belongs to the balcony, stated? When the mound or embankment is near the balcony. But in a case where the embankment or mound is distant from it, even if it is ten handbreadths high, the right to use the embankment or mound goes to the members of the courtyard. And what is considered near? Anything that is not four handbreadths removed from the balcony.

GEMARA: The Gemara comments: It is obvious that if the residents of two courtyards established separate eiruvin, and the residents of both courtyards have convenient access to a certain area, the residents of this courtyard through an entrance, and the residents of that courtyard through another entrance, this is similar to the case of a window between two courtyards. If the residents did not establish a joint eiruv, the use of this window is prohibited to the residents of both courtyards.

It is similarly obvious that if a place can be used by the residents of this courtyard only by throwing an object onto it and by the residents of that courtyard only by throwing, but it cannot be conveniently used by either set of residents, then this is equivalent to the case of a wall between two courtyards. If there is a wall between two courtyards, it may not be used by either courtyard. Likewise, if a place can be used by the residents of this courtyard only by lowering an object down to it and by the residents of that courtyard by a similar act of lowering, this is comparable to the halakha of a ditch between two courtyards, which may not be used by the residents of either courtyard.

It is likewise obvious that in a place that can be conveniently used by the residents of this courtyard through an entrance but can be used by the residents of that courtyard only by throwing an object onto it, this is governed by the ruling of Rabba bar Rav Huna, who said that Rav Naḥman said: This place may be used only by those who have access to the area by way of an entrance. Likewise, a place that can be conveniently used by the residents of this courtyard through an entrance but can be used by the residents of that courtyard only by lowering an object down to it, this is governed by the ruling of Rav Sheizvi, who said that Rav Naḥman said: This place may be used only by those who have convenient access to it.

The ruling in each of the aforementioned cases is clear. What is the halakha concerning a place that can be used by the residents of this courtyard only by lowering an object down to it and by the residents of that courtyard only by throwing an object on top of it? In other words, if an area is lower than one courtyard but higher than the other, so that neither set of residents has convenient access to it, which of them is entitled to use it?

Rav said: It is prohibited for both sets of residents to use it. As the use of the area is equally inconvenient to the residents of both courtyards, they retain equal rights to it and render it prohibited for the other group to use. And Shmuel said: The use of the area is granted to those who can reach it by lowering, as it is relatively easy for them to lower objects to it, and therefore its use is more convenient; whereas for the others, who must throw onto it, its use is more demanding. And there is a principle concerning Shabbat: Anything whose use is convenient for one party and more demanding for another party, one provides it to that one whose use of it is convenient.

In order to decide between these two opinions, the Gemara attempts to adduce a proof from the mishna: If the residents of houses that open directly into a courtyard and the residents of apartments that open onto a balcony from which stairs lead down to that courtyard forgot and did not establish an eiruv between them, anything in the courtyard that is ten handbreadths high belongs to the balcony, while anything that is less than this height belongs to the courtyard.

The Gemara first explains: It might have entered your mind to say: What is the meaning of the balcony mentioned in the mishna?

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Eruvin 83b explores the required dough measure for separating challah based on the wilderness manna portion, then details courtyard and balcony eiruv boundary heights.