How high can you go? TB Eiruvin 2

Today we begin massekhet Eiruvin. In reality massekhet Eiruvin is a continuation of massekhet Shabbat. It primarily deals with the prohibitive labor of carrying an object from one domain to another. We bumped into these discussions from time to time in massekhet Shabbat, but now they will be dealt with in greater detail.

 As an introduction to our tractate and to remind you of key terms necessary for understanding the ensuing discussions, there are four different domains. There is the rashut harabim, the public domain in which we are forbidden to carry an object four amot within it as well to transfer an object from the public domain to the private a man. Basically the public domain is a street that is 60 amot wide, goes through from one end city to the other, and 600,000 people travel along it. The rashut hayakhid, is an area that surrounded by three or four walls. Both the public and private domains are Toraitic in origin. The third domain is a carmalit which has to have an area of at least 4 x 4 amot, but is not generally used by people. Examples of a carmalit are a field or a body of water. The carmalit is of rabbinic origin and has all the same restrictions as a public domain. The last domain is a makom patur is everywhere else and the laws of carrying do not apply.

 To understand the first Mishna, you have to understand city planning during the second Temple period. Multiple houses open up to a courtyard. Multiple courtyards open up to an alleyway or what we might call a cul-de-sac, מָבוּי. This alleyway is enclosed by three of the courtyards’ walls and opens up into the public domain. Even though this alleyway is technically a private domain, the rabbis were afraid people might accidentally carry from the alleyway to the public domain and thus violate Shabbat. Consequently, they ruled that the alleyway needs a demarcation where the alleyway ends and the public domain begins. We shall learn that some only require a vertical beam, a lekhe- לחי, on both sides of the entrance, some require a horizontal beam, a koreh- קורה, across the top of the alleyway, and some require both.

“MISHNA: If an alleyway is enclosed on three sides with courtyards opening into it from three sides, and the fourth side opens into a public domain, it is prohibited by rabbinic law to carry objects in it on Shabbat. However, carrying in an alleyway under those circumstances is permitted if a cross beam is placed horizontally over the entrance to the alleyway. The mishna teaches that if the cross beam spans the entrance to an alleyway at a height above twenty cubits, one must diminish the height of the cross beam so that it is less than twenty cubits. Rabbi Yehuda says: He need not diminish it, since the cross beam enables one to carry in the alleyway even at that height.” (S him and efaria.org translation)

 The Gemara wants to know what was the paradigm used by the sages and Rabbi Yehudah when deciding their measurements. According to Rav, the sages use the paradigm of the doorway to the Heikhal of Temple, the place where sacrifices were offered up. You can find an illustration of the Tabernacle with the Heikhel on page 1520 in the Etz Hayim Humash or on page 463 in the Stone edition of the Humash. According to Rav Hisda, Rabbi Yehuda’s paradigm was a palatial entrance which could be larger than the doorway into the Heikhal.