Survey – Eruvin 2-5 (October 7-10)
The exploration begins with an entrance to a closed alley (with walls on three side and one open side) – how to define it as private space? One may have a beam across the opening, says the Mishnah, as long as it is lower than 20 cubits (about 30 feet) and narrower than 10 (15 ft.). Rab speculates that the figures derive from the structure of the Second Jerusalem Temple [mikdash] when it stood, or perhaps the Biblical description of the Tabernacle [mishkan] during the 40 years of Sinai wandering. It is interesting from an historical perspective to see that the Talmud concedes that the two terms are sometimes exchanged (likely because they served similar purposes of “divine encounter), because some modern scholars believe that the Biblical descriptions of the mishkan were actually written around the building of the mikdash instead. The reason they focus on these buildings is to determine what the maximum size of a permissible “entrance” is by Biblical definition, so they can define what size would count in order to define the alley as private space for Shabbat carrying. If the original Mishnah claims that the shape of a doorway is enough, even if wider than 10 cubits, what counts to define a doorway shape?
The other major parallel the rabbinic discussion draws on is a sukkah [booth for the holiday of Sukkot], which according to the Rabina has much more specific size parameters because it is d’oraita [from the Bible] while the rule of the entrance to an alley is only d’rabanan [from the Rabbis]. The irony is that the Rabbis are the ones who define the details of what is d’oraita – the Bible says nothing about the SIZE of one’s sukkah. And it is the Rabbis who also create their own problems: what about a crossbeam where part of it is over 20 cubits high and part is under 20 cubits high? After much discussion, the Talmud asks: what’s the decision? I’ll quote the Soncino translation directly: “Rabbah b. R. Ulla replied: The one as well as the other is inadmissible. Raba replied: The one as well as the other is admissible.” I’m glad they cleared that up! And if your crossbeam on your alley is under 10 handsbreaths high (the minimum, approximately 4 feet), don’t worry – you can always dig out some of the earth beneath it to make it tall enough!
Another problem that Abaye raises “in the name of Rabbi Nachman” is the very measurement of a cubit, which traditionally was the distance between one’s elbow and the tip of their middle finger (which of course is different on everyone). A “cubit” [amah] for the sukkah or an entrance is five “handsbreadths” [tefakhim], while a cubit for purposes of “forbidden mixtures” [kilayim – as in planting a field with two kinds of seeds] is six tefakhim. Or you can say that the standard is six tefakhim, but for kilayim one spreads out one’s fingers for each tefakh while for openings one keeps the fingers together. In either case, it’s clear that one is supposed to be more careful to give extra space when facing the possibility of a forbidden mixture. And since one can find basically no discussion in the Bible for any of these measurement debates, Rab asserted strongly that they are halakha l’moshe mi'sinai: a law given directly and orally to Moses on Sinai and then passed down orally, and thus known by rabbinic tradition but not provable from the written revelation. And in the middle of discussing possible Scriptural sources for such rules, the Talmud interjects: do you imagine these are actually written (in the Torah)? They are traditional halakha that the rabbis have supported from the Torah! We would say there’s a big difference between deriving the law from the original source and connecting it post facto to give a new rule old authority.
Indeed, this is what much of Talmudic law is trying to do. But this issue of the authority of measures and partitions is crucial to the entire agenda of tractate Eruvin – if the goal of Talmudic debate was to determine the law [halakha] that one should follow, then one should be sure that the subject of one’s debates was indeed halakha l’moshe mi’sinai and not just the invention of a later age. We today don’t need to imagine that the debates and issues go back any further than Rabbinic Judaism itself, 1800 years ago – that’s far enough back for us to feel like we’re reaching into the distant past.
Rabbi Adam Chalom
Kol Hadash Humanistic Congregation