Siman 390

The Tur wrote: "An alleyway where one of its sides is a gentile and an Israelite is on its second side, and one house of an Israelite is next to him open to the public domain and not to the alleyway, and there is a window between him and the Israelite who dwells in the alleyway—he cannot make an eruv via the window between them to take out his vessels to the alleyway via the house of the Israelite neighbor that is open to the alleyway. But if there is a doorway between them—it is permitted according to Ri, and according to Rashi even if there is a doorway between them—it is forbidden." Thus far his words. And this law has already been explained regarding a courtyard in siman 382, and the reason is as it is there, for it is forbidden for an individual to act in the place of a gentile. And there we also explained the reason for the distinction between a window and a doorway, according to the method of Ri, of blessed memory. (And the Beit Yosef wrote, even though this alleyway has only one courtyard of an Israelite, and we require courtyards—nevertheless the courtyard of the gentile is also considered a courtyard in this matter, see there.)

The Rambam in chapter 5, law 18, wrote this law in a different manner, and this is his wording: "An alleyway where one side is occupied by Cutheans and one side by Israelites, and there were windows open from courtyard to courtyard of the Israelites, and they all made an eruv by way of the windows—even though they have become like the residents of one house and are permitted to take out and bring in by way of the windows, these are forbidden to use the alleyway by way of the entrances until they lease from the Cutheans, for many do not become as one in a place of Cutheans." Thus far his words. We also brought this in siman 382, section 11, and we explained there that in my humble opinion the Rambam disagrees with Rashi, who explained in the Gemara according to the explanation of the Tur, for according to the previous law it is a great stringency, and according to the Rambam it is a great leniency, and all the more so the Rambam does not hold of the stringency of the Tur, which is the opinion of Rashi. And I am wondered at our teacher, the Beit Yosef, who brought both laws as if they do not contradict one another, and here too he brought both laws, and it requires great study.

We have already explained in siman 382, section 6, that a Kuti does not prohibit unless he dwells in one courtyard with the Israelites, or in two courtyards, one inside the other, where there is necessarily a right of passage from the inner to the outer. But two courtyards open to one another, and each courtyard has a path to the public domain or to an alleyway, and a Kuti dwells in one courtyard and two Israelites in the other courtyard—they do not need to lease the domain from him, even though he sometimes passes through them, since he has another path, and he only prohibits in the alleyway when his opening is open to the alleyway, but in the courtyards they may make an eruv between them, see there. And according to this, even when the courtyard of the Kuti intervenes between the two courtyards—they may make an eruv via the openings between them, to carry through the courtyard of the Kuti, for it is not considered an intervention since he does not prohibit. (Magen Avraham) But there are those who disagree on this, and hold that specifically when the Kuti has no opening neither to the alleyway nor to the courtyards of the Israelite, but rather a window above ten tefachim—he does not prohibit. But if he has even an opening or a window below ten—he prohibits, (ibid. in the name of the Bach) and in my humble opinion the primary view is like the first opinion.