Siman 387

The eruv and the shituf have one purpose, for the eruv connects all the residents of the courtyard, and the shituf connects all the residents of the mavoi. They have one law, as was written in the previous siman, except that they differ in two matters. In the essence of the eruv: in a courtyard, one may only make an eruv with bread; and in a mavoi, even with wine or any other thing. And in the location of the placement of the eruv: in a courtyard, one only places it in a house that is in the courtyard; and in a mavoi, one may place it even in the courtyard. And the reason is that an eruv is for the sake of a dwelling, to mix their dwellings to make them one, and a person's dwelling is not drawn after wine but after his bread. But the shituf of a mavoi is only to partner the domain of the courtyards, and a courtyard is not a house of dwelling; therefore, bread is not required (Rashi 71a). And this is the very same reason for the difference in their placement: an eruv, which is for the sake of a dwelling—a person only dwells in a house, and therefore one must specifically place the eruv in a house. But a shituf, which is only to partner the courtyards—it is sufficient when they place it in the courtyard.

And there is a question regarding this: since, ultimately, they have one intent—to make them all as if they are in one place—why do I need both? It is understandable when each courtyard made an eruv for itself; they certainly require a shituf mevoi to permit carrying in the mevoi and from courtyard to courtyard. But when they have established a shituf in the mevoi, why is an eruvei chatzerot necessary? For, ultimately, they are all as if in one place, so why further require the eruv that is in the courtyard? And it is not only necessary to ask when they made the shituf with bread and placed it in one of the houses, as is our custom, where we make an eruv for the entire city and place the matzot in the synagogue—where it is not relevant at all to subsequently make an eruvei chatzerot, since they all already dwell in one place. Rather, even if they made the shituf with wine and placed it in the courtyard, where in such cases it would not be effective for an eruv—nevertheless, ultimately, all the residents of the mevoi are already in one place.

However, thus the sages said (Eruvin 71b): "One makes an eruv in the courtyards and a shituf in the alleyway—so that the law of eruv will not be forgotten by the children." This is the wording of the Rambam in chapter 1, law 19: "Those who make a shituf in the alleyway must make an eruv in the courtyards, so that the children do not forget the obligation of eruv, for the children do not recognize what is done in the alleyway. Therefore, if they made a shituf in the alleyway with bread, they may rely upon it and do not need to make an eruv in the courtyards, for the children recognize bread." Thus far his words. And this is what he wrote in chapter 5, law 14: "If they made a shituf in the alleyway and they all forgot to make an eruv in the courtyards, if they are not fastidious about their portions, they may rely on the shituf for the first Shabbat only. And we do not permit this for them except in a case of pressing need." Thus far his words. And this is from the Yerushalmi (Hadar, law 9); this is when they made the shituf with wine or other things, and not with bread. And they forbade this matter so that the children would not forget the obligation of eruv; therefore, they only permitted it for the first Shabbat, and on the condition that they are not stingy people who are fastidious about a piece of bread, and there is no concern that perhaps they will not make an eruv for the coming Shabbat. But if they were making the shituf with bread, it is permitted even ab initio.

The Tur is more lenient, for even if they made the shituf with wine or with another substance—there is no further need for an eruv, for thus it emerges according to his opinion from the sugya of the Shas, that we are not concerned lest one forget the obligation of eruv. This is the wording of the Tur: "We rely on an eruv in place of a shituf and on a shituf in place of an eruv. For if there were five courtyards open to one another and open to the alleyway, and the courtyards made an eruv via the doorways between them—they do not require a shituf in the alleyway. And likewise, if they made a shituf in the alleyway, even with wine which is not fit to make an eruv with in courtyards—they do not require an eruv in the courtyards. The Rambam, of blessed memory, wrote that we do not rely on a shituf in place of an eruv—unless they made the shituf with bread, but my lord father, the Rosh, of blessed memory, did not write so." Thus far his words. And the first case the Rambam did not mention at all, and it requires further study.

Our teacher, the Beit Yosef, after writing the words of the Rambam, wrote: "And some say that if each courtyard did not make an eruv for itself—one may not rely on the shituf. But when each courtyard made an eruv for itself, and afterwards they joined in a shituf in the alleyway, and did not make an eruv via the doorways between them—they are permitted to use the courtyards in the alleyway via the doorways between them, for they rely on the shituf in place of an eruv. And if they made an eruv via the doorways between them and did not join in a shituf in the alleyway—the courtyards are permitted to use the alleyway, for they rely on the eruv that the courtyards made via the doorways in place of a shituf." Thus far his words. And they wondered about him, for this opinion is not found at all. (See the Bach and the Taz who raised many difficulties against him, and the Perishah wrote at length to settle his words, see there.)

Our teacher, the Rema, wrote: "And some say that we rely on the shituf in place of the eruv, even if they only joined together with wine, and similarly we rely on the eruv in place of the shituf. And above in siman 366 I wrote that our custom is ab initio to make only one shituf with flour. And it seems to me the reason is that our eruv—wherein each of the residents of the courtyard gives to the shituf—is like an eruv and shituf together, and ab initio one should not do more. And that which they required a shituf and an eruv was in the time of the Gemara, when the residents of the courtyard did not give to the shituf, but rather the courtyard made an eruv together, and one of the residents of the courtyard gave to the shituf. But in this manner, according to everyone, one makes only one shituf. And if one did more and recited a blessing over it, it is a blessing in vain." Thus far his words.

And they also wondered about him, why he must seek reasons, for since we perform the shituf with bread—is it not permitted according to all opinions? (Taz subsection 2, and Magen Avraham, and Bach). However, his intention refers to the "there are those who say" that our teacher, the Beit Yosef, wrote, that with shituf alone—one does not fulfill the obligation at all, even with bread. And to this he says that when each of the residents of the courtyard contributes to the shituf—even according to the "there are those who say," shituf alone is sufficient. And I say that all of this was to investigate according to the structure of their cities, which had courtyards and alleys. But for us, as we do not have alleys but only courtyards, and when we make an eruv for the entire city—the entire city is like one large courtyard, for because of this we apply the law of a courtyard to ourselves which requires two posts, and not like an alley which suffices with a lechi, as has been explained in siman 363; if so, it follows that for us it is only possible with one eruv and specifically with bread, and that it be placed in a house. And now it is placed in the synagogue, which is no worse than a house. It turns out that for us there is only eruvei chatzerot, and we have no shitufei mevo'ot at all. And according to this, those people who are stringent upon themselves and also make an eruv in their courtyard without a blessing—in my opinion they act ruinously and it is forbidden to do so, for this is like one who divides his eruv in a single courtyard—where the eruv is nullified, unless they do so on condition—if the city eruv is valid our words are nothing, etc. (So it appears in my humble opinion)