Eruvin 28a, b

A couple of notes from my reading on erev Shabbat:

The conversation continues about what can serve as markers to establish an eruv.  In 28a and b, the rabbis focus on different kinds of produce.

An interesting conversation arises regarding customs in different places.  Generally speaking, halacha does not follow individual customs in any one locale.  We learn that if a custom is unusual, it is not considered to be halachically important, regardless of the locale.  If the custom is judged as 'reasonable', it is considered to be halachically important only in those places that practice that custom.  However, if a custom is 'proper and worthy' but not practiced because of expense or lack of materials, it is considered to be significant anywhere that it is practiced.

More on this form of seemingly flexible but ultimately restrictive social control in another post.  

Another interesting note arises from a young child's conversation with a Rabbi, where the young child's understanding of the halacha 'wins' the halachic wrestling match.

The rabbis then move into a deeper discussion of foods that are considered to be acceptable as meals to mark the placement of eruvim.  Much of the conversation in 28b focuses on which foods are considered ritually impure or ritually pure.  As well, the rabbis discuss the amounts of food that are required to represent two meals, which is what is required to mark an eruv.

It is difficult to follow some of this conversation when I cannot picture the amounts being discussed.  Rarely do the rabbis talk about cups or quarts or litres (although it does happen).  Instead I am learning about kavs and logs and se'as.