What is the definition of a דירת עראי?

Question

The Mishnah in Gemara Sukkah 2a states: סוכה שהיא גבוהה למעלה מעשרים אמה פסולה. Rava states that the explanation of the 20 amos height limitation of the Mishnah finds its restriction in the fact that a Sukkah must be a דירת עראי. Is a דירת עראי defined by its material makeup or an abstract dimension?

Answer 1

Rava states that temporariness is not determined by the materials used to construct a sukkah. Rather, temporariness is determined by an abstract dimensional range. Any sukkah constructed up to 20 amos in height is a דירת עראי.

And, even if a person builds (or could build) his sukkah out of temporary materials above 20 amos he does not fulfill his obligation because his sukkah would occupy a dimension of קבע. As Rava states to Abaye in the Gemara: א”ל הכי קאמינא לך עד כ’ אמה דאדם עושה דירתו דירת עראי כי עביד ליה דירת קבע נמי נפיק למעלה מכ’ אמה דאדם עושה דירתו דירת קבע כי עביד ליה דירת עראי נמי לא נפיק.

Accordingly, Rashi states in his commentary on Gemara 2b that Rabbah and Rebbi Zeira did not agree with Rava’s source for the 20 amos height limitation of a sukkah because they did not want to learn out from the words שבעת ימים an abstract measurement regarding the concept of temporariness. Instead, they felt that if the words שבעת ימים could be interpreted to mean that a sukkah should be built in some sort of temporary fashion, it would have to be understood as Abaye did in the terms of the material makeup of the sukkah.

Another proof that the definition of a דירת עראי is not determined by the materials used but is an abstract range determined as 20 amos or less can be learned from Gemara 7b where Rebbi Yehuda is listed as one of eight Tannaim that hold that a sukkah is a דירת קבע on the basis that he validates a sukkah above 20 amos in height. From this we find proof for Rava’s understanding that a sukkah which is built less than 20 amos in height is in the dimensional range of what is considered a דירת עראי.

Additionally, this understanding of an abstract measurement verses a material concept of עראי and קבע is further observed in the same Gemara on 7b in referencing Rebbe’s opinion that the קבע of a sukkah is established as one that is 4×4 amos or greater, regardless of its material makeup. And conversely, Rebbe maintains that a sukkah less than 4×4 amos is a דירת עראי.

Furthermore, on the basis of an abstract measurement of 4×4 amos, the Baraisa on 3b regarding the laws of houses determines whether a house is a דירת קבע or a דירת עראי.