Yerushalmi Eruvin 7:1 ירושלמי עירובין ז׳:א׳

MISHNAH: If a window between two courtyards is four-by-four [hand-breadths] within ten [hand-breadths], one makes two eruvin but if they wish they make one eruv¹The window is simply a rectangular opening in the wall between two courtyards, not closed with glass or anything else. If the opening is at least 4 hand-breadths wide and 4 high it is usable as a door. If the lower rim of the hole is no more than 10 hand-breadths from the ground, the wall at that place is not considered an obstacle. The status of the two courtyards is as if they were connected by a real door; it is up to the dwellers in the courtyards to decide whether to treat them as one or two.. If less than four-by-four [hand-breadths] or higher than ten [hand-breadths], one makes two eruvin and cannot make one eruv²A wall 10 hand-breadths high is a partition which separates the courtyards completely. In addition, an opening less than 4-by-4 in size is difficult to use; it cannot substitute for a door..

HALAKHAH: “If a window between two courtyards,” etc. Lattice work²²If the window was closed by vertical and horizontal bars it cannot be used as door and two separate eruvin are required. diminishes it for the laws of Sabbath, but it does not diminish for the laws of presumed possession²³A person may prove ownership by a claim of lawful acquisition combined with proof of undisturbed possession during three years; for the laws of real estate properties connected by a window with bars may still be counted as one; Mishnah Bava batra 3:8.. Straw and provender do not diminish in it; pebbles and provender do diminish in it²⁴Anything which is disregarded for the rules of ditches (Mishnah 3) is disregarded for windows.. Rebbi Yose ben Rebbi Abun said, if grasses grew in it, they do not diminish it.

They asked before Rebbi Abba: Concerning what you are saying about a window between two courtyards, is it the same for a window between two houses? He told them, yes. Is it the same for a window between two roofs? He told them, yes. May one make an eruv across skylights²⁵Between the living quarters and the flat roof.? Rebbi Abba Mari said, it is a disagreement between Rav and Samuel, as we have stated there: “All roofs of a city are one domain.²⁶Mishnah 9:1.” Samuel said, up to two bet se’ah; Rav said, one may move inside them even a kor, even two kor²⁷The Mishnah does not spell out what kind of domain is formed by the roofs. For Samuel, roofs are places which are not fenced in for dwellings; they follow the rule of corrals where carrying is only allowed if the surface area is at most 5’000 square cubits. If the total area of the roofs is larger, an eruv would be ineffective; the roof cannot be part of the eruv domain of the house. But for Rav one is permitted to carry on connected roofs without limitations (even if the total area be larger than 2 bet kor, 60 bet se’ah); the eruv may be extended to the roof. The Babli has a very different tradition, 89a–90b..

Not only that the entire four-by-four [hand-breadths] must be within ten [hand-breadths] but even if part of four-by-four [hand-breadths] are within ten [hand-breadths]it is as if all four-by-four [hand-breadths] were within ten [hand-breadths]²⁸Babli 76a.. If the circumference was 96 hand-breadths, if only the most minute amount was within ten [hand-breadths] it is as if all of four-by-four [hand-breadths] were within ten [hand-breadths]²⁹If the window is square, 4-by-4 cubits, each side is 24 hand-breadths, so that the total circumference is 96 hand-breadths. As S. Liebermann points out, the Yerushalmi implies that a window 4-by-4 hand-breadths must start visibly lower (“part of it”) than 10 hand-breadths from the ground but if it is 4-by-4 cubits the most minute amount, not visible by the naked eye, is sufficient.. If it was round of circumference 90, etc³⁰This sentence is a corrector’s addition to the ms. and probably should be deleted. A circular hole is a qualifying window if it contains an inscribed square of side lengths 4. A circumference has to be about 11% larger than 16 hand-breadths to qualify as a 4 hand-breadth window or 96 hand-breadths for the 4 cubits rule..

May one reduce using utensils³¹If the window in the wall is more than 10 hand-breadths from the ground, may one use utensils on the ground below the window to reduce the distance so that it would be permissible to make a common eruv? As the Babli 77a points out the problem is that utensils may be moved on the Sabbath and therefore are disqualified as building materials.? Rebbi Ḥiyya bar Ashi said, one may reduce using utensils. Rebbi Jonah, Rebbi Isaac bar Ṭevlai: Rebbi Joḥanan said, one may not use utensils. There³²In Babylonia., they said, it is a disagreement between the Elder Rebbi Ḥiyya and Rebbi Ismael ben Rebbi Yose. One said, it is forbidden; but one said, it is permitted. He who said that it is forbidden, maybe he would forget and move it³³As noted before, utensils may be moved but utensils used as part of the building become muqṣeh; this may easily be overlooked.. Rebbi Joḥanan bar³⁴This is the scribe’s text, erroneously changed by the corrector into כד. Marius instructed to cover it with a heap of sand³⁵Arabic كوفة..

It was stated³⁶Tosephta 7:10. “Anything” seems to mean any building material.: “One may use anything to reduce, stones, bricks, a Tyrian or an Egyptian ladder if it was fastened³⁷A Tyrian ladder is very heavy and not intended to being moved. Therefore the use of such a ladder to facilitate crossing from one courtyard to the other is unproblematic. But an Egyptian ladder is light and built to being moved; its use presents all problems connected with the use of utensils. Egyptian ladders are not mentioned in the Tosephta. Rashba (ad 77a, col. 470) prefers to read in the text that only Egyptian ladders must be permanently fixed to the wall..” Rebbi Abba in the name of Rav Jehudah: Even if it was not fastened. But was it not stated “if it was fastened”? Rebbi Abba said, if it was dedicated for this purpose³⁸An Egyptian ladder is acceptable even unfastened if it is intended to be a permanent fixture at the wall.. Rebbi La instructed following this Tanna, only if it was fastened. Both Rebbi Jonah and Rebbi Yose, one in the name of Mar Uqban, and one in the name of Rav Naḥman bar Jacob: It is necessary that between two steps³⁹Of any ladder used to climb up to the window. there be less than three [hand-breadths] and each be four hand-breadths wide; the posts complement the four⁴⁰The total width of the ladder, posts and steps, must be 4 hand-breadths.. Yasa said, a block in which he carved steps reduces⁴¹A big stone or a block of wood into which steps are carved is an acceptable ladder for the rules of eruv.. In any case, the posts do not complement ten; it is like a high step⁴²These are two different statements. The length of the posts of a ladder is irrelevant for the rules of eruv; only the steps count and the uppermost step must be within ten hand-breadths of the lower rim of the window. A block of wood with carved steps is not under the 3 hand-breadths rule since the block itself is a high step.. Rebbi Yasa in the name of Rebbi Abun bar Cahana: It must be stretched four hand-breadths from the wall as separate place. Rebbi Ḥizqiah in the name of Rebbi Abun bar Cahana: The step which reduces from ten must be stretched four hand-breadths from the wall as a separate place⁴³The statement of R. Ḥizqiah explains of the one of R. Yasa. Only the step which is counted as being less than 10 hand-breadths from the window must be a domain in its own right.. Rebbi Jacob the Southerner asked: ⁴⁴This is from Chapter 1, Notes 253–255. In Mishnah 1:9 ropes represent a wall if they are less than 3 hand-breadths apart but in Mishnah 7:1 a hole is an opening only if it is at least 4 wide and high. If one brought a board of seven hand-breadths and raised it less than three from the ground, is it permitted? There you are saying, everything less than three [handbreadths] is considered closed, and here you should be saying, everything less than four [handbreadths] is considered closed. If you want to object, object to the following: If one brought a wall of slightly more than four hand-breadths and raised it less than two hand-breadths from the ground, should it come following what Rebbi Joḥanan said, what is standing and empty space combine for four hand-breadths, on condition that what is standing be more than the empty space?