When do walls make good neighbors? TB Eruvin 76, 77, 78

Thank God, I been able to maintain the discipline of studying a daf of Talmud a day. However, circumstances beyond my control made it impossible for me to write a daily blog on TB Eruvin 76 and 77. I’ve decided to combine today’s daf TB Eruvin 78 with the two previous pages all in one blog by writing about one of the major threads that unites the three dappim.

Picture two courtyards separated by a wall 10 tefachim, handbreadths, tall, and is 4 x 4 tefakhim wide. If the two courtyards are inaccessible from each other, two separate eruv hatzerot are needed. There is no way a person can unify them together to make one large courtyard. If on the other hand, there’s a breach in the wall wider than 10 amot, the two courtyards turn into one large one and only one eruv hatzerot can effectually unite both courtyards. Two separate eruv hatzerot are impermissible. Our dappim discuss ten permissible ways to allow people to join the two courtyards with one eruv. To make the two courtyards into one large one, they have to be accessible from one to the other. The technical term for accessibility in our case of a wall separating two different courtyards is “diminishing the wall- מיעוט הכותל.” A me’ute (מיעוט) or diminishment must be structured and fixed to be halakhically acceptable as a method of accessibility.

The first me’ute is a window in the wall that at least 4 x 4 tefakhim and is below 10 tefakhim on the wall. Think of this window not in modern terms, but rather just the opening that person can go from one side to the other. This opening may be either square or circular. If you like geometry then the discussion concerning the dimensions of these two openings are discussed in great detail. “Rabbi Yoḥanan said: A circular window must have a circumference of twenty-four handbreadths, with two and a bit of them within ten handbreadths of the ground, so that when he squares the window, i.e., if he forms the shape of a square inside it, it measures four by four handbreadths, and a bit of it is then within ten handbreadths of the ground.” The Gemara poses geometrical problems concerning this calculation and deals with the different required sizes between a square circumscribed by a circle and circle circumscribed by a square.” (Sefaria.org translation)

The second me’ute is to remove some stones from the wall to make a passable breach.

If a 4 x 4 tefakhim stone or a 4 x 4 tefakhim upside down basin that is firmly stuck into the ground is the third me’ute. By climbing upon the stone or upside down basin will enable a person to go over the wall and thus gain access to the other courtyard.

The fourth me’ute is a Tyrian ladder which has the required four rungs and its heaviness makes it hard to move and establishes it as part of the wall.

The fifth me’ute is two ladders, one on each side of the wall. “Abaye said: If a wall between two courtyards is ten handbreadths high, and one placed a ladder four handbreadths wide against the wall on one side, in one courtyard, and another ladder four handbreadths wide on the other side, in the other courtyard, and there are less than three handbreadths between them, i.e., the two ladders on the opposite sides of the wall are within three handbreadths of each other, even if they are not directly opposite each other, this diminishes the height of the wall. The pair of ladders is regarded as a valid passageway between the two courtyards. However, if the gap between the two ladders is three handbreadths or more, this does not diminish the height of the wall. And we only said this qualification if the wall was less than four handbreadths wide. However, if the wall was at least four handbreadths wide, then even if one ladder was greatly distanced from the other, this likewise renders it permitted. Since it is possible to walk along the thickness of the wall, the pair of ladders constitutes a passageway between the two courtyards.” (Sefaria.org translation)

The sixth me’ute is a wooden platform. “Rav Beivai bar Abaye said: If one built a wooden platform next to the wall above another platform, then if the lower platform is four handbreadths wide, it diminishes the height of the wall to below ten handbreadths. Alternatively, if the lower one is not four handbreadths wide, but the upper one is four handbreadths wide, and there is a gap of less than three handbreadths between them, it diminishes the height of the wall, as the two platforms are considered as one.” (Sefaria.org translation)

The best way of describing the seventh me’ute is a series of steps stools one higher than the next enabling the person to scale the wall. As long as one of the steps is 4 x 4 tefakhim and none are more than three tefakhim apart including the lowest step from the ground.

 The eighth me’ute is a projection from the wall and a ladder. “Rav Naḥman said that Rabba bar Avuh said: If a projection four by four handbreadths in area extends from a wall, and one placed a ladder of any width against it, if the rungs of the ladder are less than three handbreadths apart, he has diminished the height of the wall by means of this ladder and projection. The Gemara qualifies this statement: And we said this only in a case where one placed the ladder directly against the projection, so that the ladder serves as a passage to it. However, if he placed it adjacent to the projection, he has merely widened the projection, while the ladder remains separate from it. Consequently, the projection does not have any connection to the ground, and a projection that is not within three handbreadths of the ground does not diminish the height of a wall.” (Sefaria.org translation)

The Gemara asks whether trees can be the ninth me’ute and answer is yes. “Rabba said that Rabbi Ḥiyya said: The trunks of palm trees in Babylonia that were placed next to a wall between two courtyards so that people could climb on them and pass from one courtyard to another do not need to be established permanently and attached to the ground; rather, they serve to diminish the wall as they are. What is the reason for this? It is that their heaviness establishes them as connected to the ground. Although it is permitted to handle them, nevertheless, since their weight makes them difficult to move, they are considered fixed in place.” (Sefaria.org translation)

The tenth me’ute is grooves cut into the wall as steps. “Rav Yosef said to him: If there was no ladder, and one dug out the entire ladder in the wall, so that all the steps are grooves in the wall, how much must he hollow out? Rabba said to him: Those steps must reach the full height of the wall. Rav Yosef asked: And what is the difference in this case? Why must the steps reach higher in this case than in the case where the hollowed-out section was merely an extension of an existing ladder? Rabba said to him: There, where there is a ladder, it is easy to climb to the top of the wall; however, here, where there are only grooves in the wall, it is not easy to climb. If one cannot reach the top of the wall, the steps are not considered a passageway between the courtyards.” (Sefaria.org translation)

When do walls make good neighbors? The bottom line -when there is easy and fixed access, so come on over.

See the Shulkhan Arukh, Orekh Hayyim, 372: 4, 6-11, 14-15 and the Mishneh Torah, Sefer Zemanim, Eruvin 3: 2, 7 for the piskai din.