Siman 353

Two houses on two sides of a reshut harabbim, if one threw from this one to that one above ten [tefachim]—he is exempt, provided that both belong to one person or to two people and there is an eruv between them. And even though when a reshut harabbim intervenes it is impossible to make an eruv, one can say, for example, that they stand at the edge of the reshut harabbim, and their side is adjacent to a corrected mavoi, and each has an opening to the mavoi, for now they can make an eruv. (Magen Avraham, subsection 1) And it is permitted to throw any object, even garments and metal vessels that do not break. But if they are not exactly opposite one another, but rather one is higher in height and the second is lower in height—it is forbidden ab initio to throw from this one to that one, for since the throwing is not level, we fear perhaps it will fall and he will come to carry it. And it is only permitted to throw breakable vessels, such as earthenware vessels and glass vessels, for when they fall on the ground they will break and not be fit for anything, and he will not come to carry it. And even though it is possible that they will not break, nevertheless, we do not fear to such an extent. And specifically above ten, which is the airspace of a makom patur. But by way of below ten, which is the airspace of a reshut harabbim—it is forbidden ab initio to throw from a reshut hayachid to a reshut hayachid through the airspace of a reshut harabbim. In what case are these words said—when a reshut harabbim passes between them, but if a karmelit was passing between them—it is permitted in every case, for they did not decree regarding a karmelit "perhaps it will fall and he will come to carry it," since even if he comes to carry it, it would not be a Torah prohibition. (See Magen Avraham at the beginning of subsection 1, and it requires further study for this is when it comes to rest in a makom patur, and see Eliyah Rabbah who challenged him on this and the Tosefet Shabbat settles it, see there).

The Rambam wrote in chapter 15, law 4: "A ledge in front of a window that extends into the airspace over the public domain, if it was higher than ten tefachim—it is permitted to use it, for the public domain only occupies up to ten tefachim; therefore, it is permitted to use the entire wall except for the lower ten tefachim. In what case does this apply? When there was one ledge extending into the airspace. But if two ledges were extending from the wall, one below the other, even though both are higher than ten, if the upper ledge in front of the window has a width of four by four—it is forbidden to use it, because it is a domain unto itself, and the ledge beneath it is another domain, and they forbid one another, for two domains may not use one domain." Thus far his words. And it must be said that his intention is when the two ledges belong to two people, and therefore they forbid one another, for if they belong to one person, why should he not have control over both, and so wrote the Maggid Mishneh in the name of the Rashba, see there. And even though in this too there is room for precision, for the ledge is certainly judged as the holes of a private domain, and why should one forbid the other? For it can be said that since they are revealed to one another without partitions, they forbid one another (see Lechem Mishneh), and even if the lower one does not have four by four (Maggid Mishneh). And the prohibition is specifically for vessels that rested within the house, as will be explained in siman 372 (ibid.), and later it will be explained that a ledge of four tefachim is a domain unto itself, and is not called the holes of a private domain.

And if there is not four in the upper one and not four in the lower one—both use them. (Ibid. in the Rambam) And the reason is that a domain that does not have four, it is not relevant to call it by the name of an owner, since there is no matter of importance in this. And only when there is four in one of them, then the name of an owner applies also to the second, even though there is not four in it, for since the name of an owner is called upon the one, it is also called upon the second. And the reasoning is thus, for behold, this one who does not have four, it is forbidden for him to use the protrusion that has four, and automatically he also has the ability to not allow the second to use his protrusion. But when there is not four in both of them, both use the protrusions and the entire wall until the lower ten tefachim, as has been written.

And he wrote further: "If there were four in the lower one and there were not four in the upper one, he may only use the upper one opposite his window alone. But on the rest of the projection that is on the two sides of the window—it is forbidden to use, because of this one beneath it which has divided a domain for itself." Thus far his words. And the reason that opposite his window it is permitted to use, it seems to me, is because it is like the holes of a private domain, meaning that it is nullified to the window. But when it has four, it is not nullified to the window, and it is forbidden to use even opposite the window, if they restrict one another. (So it seems to me according to the opinion of the Rambam). And from his words it is implied that the projections restrict one another, even if they are not opposite one another. And the opinion of the Rashba is that they do not restrict one another unless they are opposite one another. (Maggid Mishneh). And the Rashba also disagrees regarding that which he permits to use opposite the window. (As is implied in the Maggid Mishneh, see there).

He further wrote: "Any ledge extending over the airspace of the public domain, which is permitted to be used, when one uses it, one may not take from it nor place upon it anything except earthenware and glass vessels and the like, which, if they fall to the public domain, will break. But other vessels and foods are forbidden." Thus far his words. And from the plain implication of his wording, it appears that even with a ledge four wide this is the case, and such is the opinion of Rashi (Eruvin 98b). And the Tosafot raised a difficulty, that if so, even if it is very wide, one should not use vessels that do not break. See there. And it appears to me that there is no prohibition except for anything that has the name 'ledge' upon it, and when it is very wide, the name 'ledge' is not upon it, but rather the name 'board' or 'bridge.' And it appears to me that this is the opinion of our teacher, the Rema, in section 3, who wrote: "And specifically a ledge and the like, but if it is a wide thing like a roof where the user stands there with the vessel—it is permitted to use all vessels." Thus far his words. And the opinion of the Tosafot and the Rosh is that with a ledge four wide, it is permitted to use all vessels. (And the Rema did not intend this, for if so, he should have said 'a ledge four wide,' but rather as I wrote, that it is very wide and a ledge extends from there.)

And all this is regarding protrusions that extend into the public domain. But regarding protrusions that extend into a karmelit, if there is no division of domains there, or if a single protrusion alone extends into the airspace of a karmelit whenever it is ten high—which is the airspace of a makom patur forever—it is permitted to use it, whether it is wide or narrow, and even for items that are not breakable, because they did not decree in a karmelit. Therefore, for us where there is no public domain, it is permitted to use protrusions. And we have already explained that when they do not have four, there is no division of domains in them, and most of our protrusions do not have four by four. (See Magen Avraham subsection 4 who raised a difficulty regarding what they wrote above ten, for in any case: if the window is open to them, even below ten they are holes of the private domain. And if the window is not open to them, even above ten it is a karmelit as written in siman 345 section 17, see there; and his intention is to what is written there that there are no "holes" in a karmelit, see there. And in my humble opinion it is not difficult at all, for a protrusion of four by four is not included in the category of holes of the private domain, but rather it is like a domain unto itself. And since it is not ten high, and stands above ten in the public domain or in a karmelit—it is a makom patur. And when it does not have four, it is called "holes" only opposite the window, as I wrote. But not when it is not opposite the window, and this is clear from the words of the Rambam, and examine this closely).