Defining the Walls of a Sukka

  • Rav Moshe Taragin


By Rav Moshe Taragin



Lecture15:  Defining the Walls of a Sukka



The gemara in Sukka lists two instances of invalid walls and suggests strategies for correcting these walls and repairing the sukka.  These two cases may potentially demonstrate the function and nature of the walls of a sukka, as well as the parallels and differences between sukka walls and the walls used to define zones for Shabbat. 


Without question, the primary element of a sukka is its sekhakh.  Are the WALLS merely sekhakh “holders” or do they also function as vital structural elements within a sukka?  For example, there is a halakha le-Moshe mi-Sinai permitting a sukka with two perpendicular walls with a small wall extending from the “other” side.  This certainly suggests a non-essential role for walls of a sukka; as long as the walls define the “sukka-space” and serve as a platform for overhanging sekhakh, the sukka is kosher.  Rashi, in fact, in his initial comments to the massekhet (2a s.v. ve-shechamta), asserts that the name “sukka” derives from the term sekhakh.   


There are two scenarios introduced by the gemara which might shed light upon this question. The first scenario introduced by the gemara (4a) concerns a sukka whose walls are shorter than the required ten tefach minimum.  The suggested solution is to dig a pit within the sukka area so that the combined height of the wall and the depth of the pit if at least ten tefachim.  The gemara conditions this solution upon the pit being dug within three tefachim of the sukka wall.  Although this condition is logical (as less than three tefachim is always considered “connected” based upon the principle of lavud), a parallel gemara in Shabbat (7b) does not mention this requirement.  That gemara, in discussing the creation of a private domain for the purposes of carrying on Shabbat, proposes a house whose walls are almost ten tefachim tall and whose roof completes the necessary height.  Effectively, the outer wall of the house combined with the width of the roof amounts to ten tefachim, but the inside of the house does not contain a ten tefach airspace.  The gemara suggests the same solution of digging a hole within the house to “complete” the requisite height.  However, in this instance the gemara DOES NOT demand a proximity of less than three tefachim between the wall and the pit.  This question bothered most Rishonim and different answers were suggested. 


In his comments on the Rambam (Hilkhot Shabbat 17), R. Chaim Soloveitchik develops a novel idea about the role of a wall in defining different Shabbat “zones.”  He claims that a reshut ha-yachid, a private domain, is not defined by the ACTUAL presence of WALLS.  As long as the area is surrounded and protected, it is deemed separate from the hustle and bustle of reshut ha-rabim, a public domain, and it is defined as a reshut ha-yachid.  Some of the general applications suggested by R. Chaim include:


1)    The ability to form walls from material that is forbidden for use and designated for burning. Although these materials cannot usually be employed for halakhic purposes, since ACTUAL walls are not necessary, “protection” and “barrier” may be achieved with any material. 

2)    The ability to define a raised platform as a reshut ha-yachid.  Although ACTUAL walls may not exist, the platform is only accessible to the public thoroughfare by climbing a height of ten tefachim; this area can thereby be defined as reshut ha-yachid. 


R. Chaim explains the “leniency” of the aforementioned gemara in Shabbat (7b) in this manner.  In this case, digging is required, not to generate ACTUAL walls, but to create a separation of ten tefachim from the public area; thus, the pit dug in the house may be at a distance greater than three tefachim from the walls. 


R. Chaim did not write explicitly about the parallel scenario of digging a pit to complete a sukka, but the implications of his statements are obvious.  Digging a reshut ha-yachid wall for the purposes of Shabbat does not require proximity between wall and pit because no ACTUAL walls are being generated.  If the gemara DOES require a less than three tefach proximity between wall and pit for a sukka, it probably indicates that, unlike a reshut ha-yachid, a sukka needs ACTUAL walls and not merely DEFINED SPACE.  Although R. Chaim did not actually write about this in his sefer, the Rav zt”l quotes him as articulating this contrast between Sukka and Shabbat.  Effectively, this stringency of Sukka convinces R. Chaim that the walls of a sukka are not just space-definers but VITAL ELEMENTS of a sukka. 


Not all Rishonim agree with this logic, however.  For example, Tosafot on Shabbat (7b) suggest a solution to the Sukka - Shabbat contradiction that may imply that the walls are, in fact, non-essential in the case of a sukka as well.  Tosafot attribute the three tefach stringency unique to sukka as a function of requiring walls close to the sekhakh.  They cite the gemara in Sukka (6b), which derives the number of halakhic walls necessary for a sukka from the use of the term “sukka” in the Torah.  The literal definition of “sukka” is sekhakh, and this indicates that the walls must be close to the sekhakh.  To ensure a wall-sekhakh dynamic, the pit and the walls must be within three tefachim of each other. If the walls are more than three tefachim distant from the pit, they are too far from the kosher sekhakh to be associated with that sekhakh. Thus, although the walls are not merely “space definers” as in the case in Shabbat, they are still not essential sukka elements. 


Similar logic may emerge from a third solution to this contradiction suggested by the Tosafot Yeshanim in Shabbat (7b).  In essence, the three tefach proximity clause between wall and pit is ALWAYS required – both for Shabbat wall correction as well as sukka wall repair.  Only the SPECIFIC situation in Shabbat (7b) allows a combination of pit depth and wall height even at distances greater than three tefachim.  The particular house described by the gemara in Shabbat possessed a ten tefach wall on the outside by including the roof.  In ADDITION to this requirement, a reshut ha-yachid requires a ten tefach “SPACE” – which this house doesn’t contain.  Since the digging was aimed at providing SPACE and not walls or separation from the outside reshut ha-rabim, the digging can occur beyond the three tefach limit. 


According to this view, the “less than three tefach” condition is universal; only the specific case in Shabbat (7b) allows a greater distance.  Consequently, the three tefach limitation DOES NOT indicate that a sukka wall is anything other than a space definer.  The qualification is universal and nothing new can be discerned about the nature of sukka walls base on it. 


A second case discussed by the gemara (4b) concerns a sukka whose walls are too high.  One solution (discussed in the previous shiur) would be to construct a platform within four amot of the walls, allowing the walls to “move” toward the height-reducing platform through the device of dofan akuma.  If this solution is impossible, the gemara considers building a sizable platform possessing the seven by seven tefach dimensions of a sukka.  If this platform is also ten tefachim high, Abaye validates this as a SEPARATE sukka located under kosher sekhakh.  We routinely witness the phenomenon of gud asik, whereby halakhic walls may be “extended” vertically.  The ten tefach high base of this platform can be viewed as a halakhic wall; extended upward toward the sekhakh, it forms an inner kosher sukka within the larger invalid one. 


Rava responds that this “gud asik” solution is unacceptable because we require “mechitzot nikarot”- discernable walls.  Understanding Rava’s rejection of Abaye’s suggestion may provide additional insight into the nature of sukka walls. 


Perhaps Rava disqualifies the application of gud asik for a platform.  The base of the platform is indeed ten tefachim high but, since the platform is solid, the “walls” of the base do not enclose any space.  Is gud asik a method of imaginarily stretching any ten tefach construct upward or does it only operate with something defined as a halakhic WALL?  This question can be posed about all of the “virtual walls” offered through halakha le-Moshe mi-Sinai.  Can they be applied to “create” walls out of matter or only to stretch pre-existing halakhic walls to different coordinates?  Perhaps, then, Rava objects to the application of gud asik in the scenario of a solid platform.  R. Chaim (in his comments to Hilkhot Sukka 4) suggested this understanding based upon a Ramban on Shabbat (99b), who severely limits the reshut ha-yachid qualities of a ten tefach platform built in a public thoroughfare.  Ultimately, according to the Ramban, Rava’s rejection of gud asik was not a statement indicating the unique nature of sukka walls; rather, he was rejecting gud asik for the base of a platform. 


In contrast, many Rishonim, including the Ran and the Ritva, interpret Rava’s rejection based on a sukka’s unique requirements.  Gud asik MAY be applied to a platform base for SHABBAT applications.  But a sukka requires actual definable and palpable walls – not virtual walls formed through gud asik!  This understanding of the sugya reaffirms the essential role of walls within the overall structure of a sukka.  Just as the less than three tefach qualification indicated the requirement of ACTUAL and essential sukka walls, Rava’s rejection of gud asik does as well. 


Intriguingly, the Ran attributes this unique requirement to a sukka’s status as a dira.  In addition to the geometric requirements of walls and sekhakh, the sukka must also be serviceable as a dira, a residence.  This association between Rava’s rejection of gud asik for a sukka and the need for dira is reminiscent of a different position of Rava’s.  An earlier gemara (4a) considered a sukka whose walls were exactly ten tefachim high but whose sekhakh protruded into this ten tefach airspace.  Abaye develops a halakhic mechanism for “ignoring” this infiltrating sekhakh:  if the volume of LOW and PROTRUDING sekhakh is insufficient to provide actual shade, the sekhakh may be ignored.  Although the sekhakh ACTUALLY invades the requisite ten tefach airspace and reduces it, this “low mass sekhakh” is rendered halakhically irrelevant.  Rava rejects this solution and disqualifies such a sukka.  He refers to this situation as dira serukha - a cramped residence. 


It seems as if Rava and Abaye are twice debating the very same issue.  Abaye views a sukka in abstract geometrical terms.  By generating proper walls and sekhakh and placing them in appropriate space, a halakhic sukka can be produced.  Even though the sekhakh invades the ten tefach airspace, it can be nullified if insufficient in volume.  Similarly, the walls forming the base of a platform can be “halakhically/geometrically” extended to create virtual walls of a sukka.  In both instances, Rava objects to these “computer” models of a sukka.  In each case, although the sukka possesses the requisite components, it does not facilitate comfortable residence.  Although the invasive sekhakh can be ignored, it still inconveniences the person and creates a cramped experience.  Similarly, although virtual walls can be extended from the base upward, such a sukka does not possess a sheltered or confined experience.  Thus, in these two debates, Rava and Abaye may be disputing the core definition of a sukka: an abstract model of walls and sekhakh or an actual dira capable of supporting comfortable residence. 


In his commentary on the Rambam, the Brisker Rav explains the first machloket between Abaye and Rava in this fashion.  In his view, the debate about sekhakh invading a ten tefach airspace reflects this point.  He does not connect it to the second debate about the viability of gud asik for sukka purposes, however.