Siman 373

There are times when two houses may make an eruv together, even though the reshut harabim intervenes between them, such as two people who dwell in two upper stories facing one another, and the width of the reshut harabim intervenes between them. And from the two upper stories two balconies protrude facing one another, and they are wide planks that protrude from the walls of the upper stories facing one another, and they are higher than ten from the ground, and the two balconies do not reach one another. If one placed a plank four wide from this one to that one—it becomes like an opening, and if they wished, they may make an eruv as one, and if they wished, each one may make an eruv for himself, for this is like two courtyards with an opening between them. And one must fix the plank with nails, so that it does not wobble and he does not remove it on Shabbat. (See Magen Avraham subsection 1) And if you should ask, does not the reshut harabim intervene between them, however, above ten it is not a reshut harabim, as was written in siman 345.

And specifically when the balconies were opposite one another. But if they were not opposite one another, such that one was drawn to the east and one was drawn to the west—they cannot make an eruv together, even if they placed a board four handbreadths wide from this one to that one, for the board would come from one corner to the other corner, and people do not make an opening in a corner. (Ibid. subsection 3) And even though this is not a comparison, and regarding a wall with a ladder it was explained in the previous siman that since the wall is four handbreadths wide we are not concerned that the ladders are not opposite one another, nevertheless here at a height in the air, if the passage is not opposite one another, it is not a proper passage even with a width of four handbreadths, for he is afraid lest he fall; and similarly if one is higher than the other. And this is when it is drawn from the other three tefachim or higher than the other three tefachim. But if they are within three of one another, whether in distance or in height—it is properly considered an opening, for anything less than three is considered lavud, and it is as if they are placed equally.

Our teacher, the Rema, wrote: "And if the distance between them is not four—even without a board, the law is also thus." Thus far his words. That is to say, that which we require a board is because they are separated from one another by a great deal. But if they reach one another, a board is not needed; and even if they do not actually reach, if there is only not a distance of four tefachim, they may step across it and can make an eruv as one. And if they actually reach one another, or are within less than three, it appears that they only make one eruv and not two. And so it is taught in the Tosefta at the beginning of chapter 8, that even with less than four, they make one eruv. This is the wording of the Tosefta: "Two balconies opposite one another in the reshut harabim, if there are four tefachim between them—they make two eruvin and do not make one. Less than this—they make one eruv and do not make two." Thus far its words, and it is speaking of without a board. (And it is a great wonder that the version of the Rif and the Rosh on the Mishnah of the window (78b) is also thus, as they wrote: "And so too two balconies opposite one another—they make one eruv and do not make two. Less than this—they make two eruvin and do not make one." See there, and so it is in the Remazim. And it is a wonder regarding the Tur and the Beit Yosef that they did not mention anything of this, and also this 'less than this' has no reason. And were I not afraid, I would emend their words like the Tosefta. And in the Yerushalmi on this Mishnah it says: "There is one who teaches they make two and not one, and there is one who teaches they make one and not two. He who says two, less than this—with a board; he who says one, less than this—in the space." Thus far its words, and the two versions were mentioned, and it requires explanation, and examine it well.)

And according to this, the laws of balconies are as follows: that if they reach one another, or are within less than three [tefachim]—they make one eruv and not two, unless some of them reach one another and some do not reach, and in the place where they reach there is no more than ten amot, for then if they wished—they make one eruv, and if they wished—they make two. And if they are four [tefachim] distant and he did not place a plank—they make two eruvin and not one. And if they are distant by less than four, according to the Tosefta—they make one eruv and not two. But our teachers, the Tosafists, wrote (78a, s.v. "v'chen," see there) that [if it is] less than four—if they wished they make one eruv and if they wished two. And when he placed a plank from one to the other, if the plank is less than ten amot or exactly ten and it is not the full width of the balconies—if they wished they make one eruv and if they wished two, and if the plank is the full width or more than ten amot—they make one eruv and not two. (And so it appears in the Magen Avraham, subsection 2, and the words of the Taz, subsection 2, are very forced, and so wrote the Eliyah Rabbah, and examine it closely.)