David's Siyum on Eiruvin

Introduction to Last Mishnah in Messechtas Eiruvin

I will be making a Siyum on Messechtas Eiruvin. Eiruvin is a continuation of Mesechtas Shabbos.

On Shabbos you are not allowed to carry from a Rishus HaYachid--a private area--to a Reshus HaRabim--a public area--which means you generally cannot carry from your house into the street or more than 4 Amos in the street.

The Chachomim expanded this to say that you cannot carry from your house to a common courtyard (a Chatzer) even though there is no Reshus HaRabim involved or from a Chatzer --to a Mavoi--an alleyway. An alleyway connects a number of Chatzeiros.

to allow you to carry the Chachomim said you need to create an Eiruv Chatzeiros or a Shituf Muvaos. this allows the many people living in these places to carry.

In addition, when it comes to an alleyway, the Chachomim required that at the opening to the alleyway you place a Koreh (a board across the top) or a Lechi (a strip of material on the side of the opening). This way it looks like it is closed up and the alley way is fully surrounded.

The final Eiruv is an Eiruv TEchumin. The Chachomim prohibited you from walking more than 2000 Amos outside the city limits. if you wanted to walk further, you needed to make an Eiruv Techumin at the edge of the 2000 amos which would then allow you to walk an extra 2,000 Amos.

The end of the final Perek of Eiruvin describes many Kulos that existed in the Beis HaMikdash when it came to Shabbos. All of these cases were cases of Shevus--an Issur Derabanan.

So the Mishnah ends with a statement from Rabi Shimon tying together the last part of the Perek to the whole Mesechta and explains how is it that the Chachomim were lenient in the Beis Hamikdash and when it came to Eiruvin. He explains that all of these cases were cases of Isuur Derabanan. And in such cases the Chachomim could be make exceptions to the rule.