Sukka 20 a, b

It is time to roof the sukka.  But what if we don't have easy-to-find schach?  Amud (a) continues the examination of sukka roofing requirements with a special focus on matting.  The mats discussed are made of natural fibres - why not use a mat to roof a sukka?  The rabbis teach us about specific questions we should ask about mats.  Are they small or large mats?  Are they mead to be slept upon?  Are they susceptible to ritual impurity due to contact with a corpse?  What about ritual impurity with regard to treading?  If the mat might become ritually impure, it cannot be used as roofing.

Among other things, amud (b) teaches us a specific consideration regarding mats as roofing.  If the mat has an upturned edge, it is not fit to use as roofing.  This is because the upturned edge is defined as a 'wall'.  Once it has a 'wall', the mat attains the status of 'vessel'.  Vessels are susceptible to ritual impurity.  

Our daf ends and Perek II begins.  We are introduced to a new Mishna that teaches about sleeping: if we sleep beneath the bed in the sukka, we have not fulfilled our obligation.  Rabbi Yehuda tells us that an old custom of sleeping beneath the bed didn't bother the Elders.  Rabbi Shimon adds a story about Rabban Gamliel's Cannanite slave, Tavi, who slept beneath the bed.  Rabban Gamliel defended Tavi, saying that slaves are exempt from time-bound, positive mitzvot.

The Gemara begins its examination by looking at the 10 handbreadth height requirement.  They continue their examination by considering the legal status of a tent.   Beds and tents could have similar status regarding ritual impurity.

It is interesting to me that the rabbis spend so much time understanding and explaining what we cannot do and why we cannot do it.  Why not simply impose their understandings of what we must do?  Our tradition is founded upon this desire to debate, to understand, to argue, to explain.  I suppose that the study of daf yoni is simply one way of entering that tradition.  It is impossible to truly debate without understanding what it is that we are debating!