Reducing the Height of a Sukka Higher than Twenty Amot

Having disqualified a sukka whose height is above twenty amot in the first mishna of sukka, the gemara (3b-4a) considers the efficacy of filling in the bottom of the sukka with “filler,” thereby reducing the height to a permissible level of below twenty amot. 
 

The gemara cites a machloket between Rabbi Yosi and the Rabanan in massekhet Ohalot regarding a similar situation.  A dead body not only conveys tuma through physical contact; it also causes tuma to "permeate" any item under the same shared structure (tumat ohel).  Although the tuma permeates the entire sheltered airspace, it does not extend above the roof or below the floor or convey tuma to items located on the exterior of the sheltered area.  However, if the tuma becomes "retzutza," contracted – lacking a surrounding envelope of a tefach of airspace - it can pass even though solid ceilings and floors and deliver tuma to items above or below the exterior of the ohel.
 

The mishna in Ohalot (15:7) addresses a situation in which an envelope of a tefach exists, but the space was filled in with material such as dirt, pebbles or straw.  Although there are some differences depending upon the material, the Rabanan generally ignore the presence of the filler, unless one has been "mevatel," - actively disowned any interest in further use of the said materials; without bittul, we ignore the "filler," the tefach envelope remains, and tuma does not extend beyond the ceiling or floor.  The filler is only considered a significant presence if one has been mevatel it. In contrast, Rabbi Yosi believes that as long as the owner has no pending plans to utilize the materials, their presence reduces the airspace and creates contracted tuma capable of spreading even through ceilings and floors.
 

The gemara in Sukka assumes that the identical machloket would pertain to the scenario of filling the floor of a sukka to reduce its height.  According to the Rabanan, only by being mevatel the materials can the owner effectively reduce the floor by adding filler, whereas Rabbi Yosi would recognize the reduction of space even if the material was placed there without pending designs for removal.
 

The Meiri raises a seminal question that could drastically affect the way we understand the mechanics of this height reduction.  The gemara (2a) suggests various reasons that a sukka higher than twenty amot would be pasul.  Some ascribe the disqualification to the distance separating the person from the sekhakh.  Rabba, for example, demands that a person visually see the sekhakh, and a distance greater than twenty amot precludes this.  Rabbi Zeira mandates sitting under the shade of sekhakh, and sitting more than twenty amot beneath the sekhakh makes this impossible.  These opinions would clearly endorse height reduction through “fillers;” by reducing the distance separating the man from the sekhakh, the sukka can be validated.  Of course, placing transitory elements to reduce the height would be meaningless, just as attempting to fulfill the mitzva by constantly jumping to reduce the height disparity would be absurd.  The reduction must be permanent and sturdy; Rabbi Yosi and the Rabanan debate (as they do in Ohalot) whether active bittul is required to make the filler permanent or whether mere deposit without intent to remove suffices.  Either way, the filling must be serious and permanent.
 

A third suggestion was offered to explain why a sukka higher than twenty amot is invalid. Rava suggests that a building higher than twenty amot is too permanent a structure to serve as a sukka, which is meant to be a temporary dwelling, a dirat ara'i. In fact, we typically rule in accordance with Rava, and most Rishonim are inclined to adopt his position in this instance as well.  How can Rava’s position be reconciled with the option of height reduction? If one adds filler to the bottom of a sukka, the walls are still too high and the structure is still too permanent.  Height reduction can close the gap between a PERSON and the SEKHAKH, but can it render structural changes to the sukka itself, transforming a twenty amot permanent structure into a shorter temporary dwelling? It was precisely this question that inspired some Rishonim to uncharacteristically rule against Rava and attribute the disqualification of a higher than twenty amot sukka to non-structural reasons (as Rabba and Rabbi Zeira did).  In his comments to the Rif (who rules like Rava), the Ra’avad mentions these opinions.
 

The Meiri offers a groundbreaking response, explaining how the machloket still makes sense according to Rava's approach.  By adding these fillers, a person effectively raises the level of the actual ground  and lowers the height of the architectural structure.  By remapping the landscape, a person can redefine the structural dimensions of the sukka.  Even if a sukka higher than twenty amot is structurally invalid, adding material can reduce its actual height.  Filling in material does not merely REDUCE the distance between a person and the sekhakh; it ADDS to the LAND or ground, and the walls are thereby reduced in height.
 

The two models of understanding the purpose and effectiveness of fillers may influence several secondary questions.  For example, when performing bittul, must the person disengage from these materials forever or merely for the seven days during which he plans to sit in this sukka?  Rashi (3b and 4a) claims that a seven day bittul suffices, whereas the Ritva and Rabenu Chananel demand an absolute and everlasting bittul.  Quite possibly, the term of the bittul would reflect the purpose and effect of bittul.  If bittul merely seeks to reduce space, perhaps a seven day bittul would be sufficient; as long as the filler is semi-permanent, the space has been reduced.  If, however, the bittul seeks to add to the ground, raising its level and thereby reducing the height of the walls, perhaps an interminable bittul is required; otherwise, the filler cannot be deemed an integral part of the land.
 

Another question regarding bittul is whether it must be verbally articulated or if it is sufficient for the person to internally commit to bittul.  Again, Rashi and the Ritva debate this issue, with the former demanding verbal articulation while the latter allows internal decision.  The Ritva questions why bittul should require spoken words; bittul is a personal act that can be executed internally.  Perhaps the proponents of verbal bittul see its role as redefining the ground and raising its level.  A landfill can only be created if the filler has been objectively designated; it must be declared as such, and the public announcement conveys the new status to this material.
 

In summary, the questions of the term and method of bittul may revolve around the issue introduced by the Me'iri. If bittul is intended to merely reduce space in a semi-permanent manner, it may be sufficient to cognitively delegate the filler for the necessary period (seven days in the case of a Sukka).  If, however, the land is being redesigned, perhaps verbal articulation is necessary and the filler must be designated forever.
 

Although this assertion of the associated logic of the two questions is appealing, it seems as though Rashi and the Ritva did not accept the linkage between these questions.  Rashi demands verbal bittul but only for seven days, whereas the Ritva allows mental bittul but requires an interminable one.  Perhaps they did not believe that both questions were determined by the same logic.  Alternatively, they each may have viewed bittul as REMAPPING the land, but each believed that one, AND ONLY ONE, factor was necessary and sufficient to confer this status.  According to Rashi, if the bittul is articulated, the land can be redefined even if the bittul is term-limited.  According to the Ritva, the more important and decisive factor is whether the bittul is endless.  If so, the land can be redefined even if the bittul has not been verbalized.
 

Having discerned these two models for bittul in the debates between Rashi and the Ritva, we may be able to better understand the primary machloket between Rabbi Yosi and the Rabanan.  Perhaps the tana'im debate this very issue and reach different conclusions about the necessity of bittul.  Rabbi Yosi only demands SPACE REDUCTION; in the situations of reducing the envelope of tuma as well as lowering the height of sekhakh, merely eliminating space in a semi-permanent manner is sufficient.  As such, no formal bittul is required; as long as the material is placed without intent to remove or otherwise utilize, the space has been eliminated.  The person is now more proximate to the sekhakh and the tuma does not enjoy the tefach envelope.  The Rabanan, however, believe that merely eliminating space is insufficient.  The actual ground of the sukka must be RAISED and the architecture of the house must be ALTERED.  To achieve these structural changes, actual bittul must occur and not mere placement of materials without intent to remove.
 

Of course, if we view the machloket in this manner and assert that the Rabanan - by requiring bittul - demand structural re-engineering, it would be logical to expect them to require verbal bittul and/or interminable bittul.  This would coincide with their view of bittul as raising the land mass or reshaping the home.  Those Rishonim who do not require both conditions, and certainly those who don’t require either, would probably interpret the debate between Rabbi Yosi and the Rabanan in a different manner.  They might not want to suggest that the Rabanan believe that bittul must alter the land mass; if that were the case, a more potent form of bittul would be necessary.
 

Viewing the Rabanan this way and interpreting the stringencies of bittul (verbalization and interminability) as stemming from bittul’s role in changing the actual STRUCTURE of ground and buildings may help explain the ABSENCE of such stringencies in a third scenario of space reduction through material filling.  The mishna in Eiruvin (78b) describes the mitzva of eiruv chatzerot, which demands unifying all the tributary homes that feed a courtyard to allow carrying from home to chatzer or from chatzer to home on Shabbat.  Typically, distinct chatzerot cannot be unified within one eiruv, but rather must be allocated independent eiruvin.  The mishna speaks of two chatzerot separated by a deep furrow as being separate courtyards.  However, if the furrow is filled with material and passage between the two chatzerot is enabled, they can join in a common eiruv.  The ensuing gemara validates dirt and stones as a filler, since they are muktzeh and won't be removed for the duration of Shabbat.  This gemara suggests that bittul can be TEMPORARY, since the prohibition of muktzeh will expire after 24 hours, effectively terminating the bittul, leading many to rule that only temporary bittul is necessary, as in the aforementioned comments of Rashi.  The Rambam, however (at least according to the Maggid Mishna’s view in Hilkhot Sukka 4:13), requires permanent bittul in the case of putting filling in a sukka, but in his comments in Hilkhot Shabbat 3:12 endorses the filling of the furrow with dirt because it would not be removed for the duration of Shabbat.  How could the Rambam allow temporary bittul for Shabbat if he requires permanent bittul for sukka?
 

Perhaps the Rambam distinguishes between filling a sukka and filling a channel that divides two chatzerot.  In the former instance, the land has to be raised and the landscape structurally altered; only interminable bittul can accomplish this.  However, to connect two chatzerot and allow a common eiruv, merely enabling ACCESS is sufficient.  As long as PASSAGE between the two courtyards is possible, the two can share a common eiruv.  To accomplish this goal, temporary bittul, for the duration of Shabbat, suffices.  The stringency of permanent bittul was only stated in the cases of sukka and tuma, where actual structural changes were necessary.  Instances of mere space filling or reduction do not require such intense forms of bittul.  See Even Ha'azel in his comments to the Rambam who draws this very distinction.