Eruvin 10

 
We have previously discussed how a קורה (crossbeam) or a לחי (sidepost) placed at the entrace of a מבוי enable carrying in the מבוי. However, as should be clear from the ongoing Talmudic discussion, while a קורה and a לחי must have certain physical properties, their function is primarily symbolic, and thus the first teaching of the Mishna (Eruvin 1:1, 2a)* discusses the height – rather than the size – of the קורה, because a core requirement of a קורה – and similarly, as discussed in today’s daf (Eruvin 10a) with respect to the לחי – is that it be seen.
However, while there are times when symbolic beams or posts are sufficient reminders of a division between a רשות היחיד (private domain) and a רשות הרבים (public domain), there are times symbolism alone is insufficient.
In today’s daf (Eruvin 10a-b) we address this point as a follow-on from the second teaching of the Mishna (Eruvin 1:1, 2a)* concerning an entrance to a מבוי that is wider than 10 amot (approx. 5 metres) where we are taught ‘ימעט’ – meaning that for the symbolic קורה or לחי to function at the entrace of a מבוי, something must be done to decrease the entrance of the מבוי.
Initially, Levi quotes a Beraita stating that a way to decrease the entrance of a מבוי that is wider than 20 amot (approx. 10 metres) is to נועץ קנה באמצעיתו ודיו – ‘thrust a post [in the ground] in its middle [of the entrance] and this is enough’, meaning that by placing a post in the middle of the entrance to the מבוי, this post would – in a symbolic way – divide in the entrance of the מבוי into two.
However, as Levi explains, the halacha is not in accordance with this particular Beraita, and we are then taught that the way to solve this problem is to place a board, which is at least 4 amot (approx. 2 metres) long, down the length of the entrance of the מבוי to create two distinct entrances to the מבוי.
Based on all this it should be clear that while symbolic beams and posts solve some halachic problems, there are times when the solution to a halachic problem generated by significant physical dimensions itself needs to have significant physical dimensions.
Like a מבוי itself, there are times in life when a symbolic gesture is sufficient to communicate a feeling or a message. But there are also times when the right response to a problem of significant proportions are significant actions.
And knowing which to use at which time requires – like the study of Massechet Eruvin itself – wisdom, reflection, and divine inspiration.
*nb. based on what I have explained, it is clear that the first Mishna (Eruvin 1:1, 2a) comes to teach us that while a קורה and a לחי are symbolic solutions, and while certain problems such as wide entrances to a מבוי require physical solutions, the halachic concept of a צורת הפתח – ‘a form of a doorway’ – which may, on first glance, appear to be a symbolic solution, is – in fact – a physical solution.