Chapter 8, Mishna 2, 3
An eruv techumin, joining of Shabbos boundaries, requires enough food for two meals from each participant. How much food is that? We measure using egg volumes. For larger quantities of grain, we use the Biblical se’a, whose volume equals 144 eggs. But this was changed in the Second Temple period, and again after the Destruction. When baking bread, how much must we make in order to fulfill the Biblical obligation of removing a portion for the priests, and thus be required to recite a blessing? How much food should a person eat on an average day? We’ve studied eruv chatzieros for neighboring courtyards and their common areas. What about neighboring residential areas where one is above the other, as in the case of an apartment building? Must they make a joint eruv? What happens if the don’t?