Eruvin 9

Out of bounds.

Today’s daf includes a quick but important reference to the idea that some ideas are beyond the scope of rabbinic conversation or outside the bounds of permitted discourse. To understand how this case is raised, let’s first take a quick look at the context.

For several pages, the rabbis have been debating the particulars of a beam used to seal off an alleyway to permit carrying with it on Shabbat. We have seen that the beam is only a symbolic boundary, not an actual one, so does it need to actually even reach the entire width of the alleyway entrance or can there be a gap between the beam and the walls?

The rabbis are able to entertain this possibility because of a concept called lavud (joining). The principle of lavud allows that even if two objects aren’t physically in contact with one another, symbolically they are if that is the clear intent. On today’s daf, the rabbinic imagination pushes the concept lavud to the extreme: What if a beam is suspended on a post in the middle of the alley but does not touch either wall? Is that sufficient to mark the alleyway for carrying on Shabbat? The Gemara determines that it is.

Now, Rabbi Zakkai appears on the scene to poke a hole in this argument.

Rabbi Zakkai taught the following beraita before Rabbi Yoḥanan: The area between the side posts and beneath the cross beam has the legal status of a karmelit, and it is forbidden to carry in it. Rabbi Yoḥanan said to him: Exit and teach this halacha outside.

Rabbi Zakkai’s teaching makes a logical point. It’s one thing to say the suspended beam itself constitutes a symbolic boundary, but surely the empty spaces between the beam and the walls aren’t covered by it. But Rabbi Yohanan won’t entertain this possibility. The idea is out of bounds. Pok t’nei l’vara, he tells Rabbi Zakkai, using a term that appears throughout the Talmud to delineate certain bounds of permitted discourse. Go teach this outside.

Every rabbi has a pedagogy and curriculum, and here we get a glimpse at Rabbi Yohanan’s. What Rabbi Zakkai says is not heresy – it’s still a received rabbinic tradition. But for Yohanan, it is beyond the scope. If Rabbi Zakkai wants to talk about it, he needs to leave the study hall.

What’s fascinating here is that it is an appeal to rationality and empiricism that is deemed out of bounds. Rabbi Yohanan and his colleagues are embedded in an imaginative argument based on the symbolism of the beam. Rabbi Zakkai wants to bring them back to earth – literally.

Often we want to live in the realm of imagination. When we read or watch science fiction or fantasy, the suspension of disbelief – the intentional rejection of critical thinking – is what enables the creation of an immersive environment (and our enjoyment!). The last thing we want is that bubble to be burst.

Perhaps that’s what Rabbi Yohanan’s exclamation is all about – not an expression of fundamentalism, but an appeal to just live for a moment in the possibilities of the world of imagination.

Read all of Eruvin 9 on Sefaria.

This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on August 18, 2020. If you are interested in receiving the newsletter, sign up here.

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