Chapter 7, Mishna 4, 5
When two courtyards are separated by a significant haystack, they lose the option to make a joint eruv. What is a significant haystack? May animals eat from it on Shabbos? How do we merge courtyards with respect to carrying on Shabbos via a shared alleyway? How do we officially acquire an object that was gifted to us? Can one acquire a share in an eruv without one’s knowledge? Also some rulings from the Elders of Pumbedisa regarding one who recites the kiddush over wine, when it is permitted to desecrate Shabbos for health reasons, and trees used in idol worship.