Shabbat 9: Thresholds, Activities Avoided Before Shabbat

Some points from today's daf in amud (a):

• a threshold between two domains is part of the private domain when the door is open and part of the public domain when the door is locked
• partitions, boundaries are part of many halachot of Shabbat, both definite and symbolic
• the principal of lavud teaches that spaces less than three handbreadths do not actually exist

In amud (b) we are introduced to a new Mishna.  It teaches about the halachot of Shabbat that are based on times of day.  We begin with  activities that should not be done before Shabbat begins:

• One cannot sit with a barber near mincha until one has recited the afternoon prayer
• One cannot enter the bathhouse and one cannot enter work in a tannery
• One cannot begin to eat a meal nor to sit in judgement before one prays
• If one has already begun these actions, however, one need not stop them to recite the Amida
• One might have to stop these activities to recite Shema

The Gemara clarifies:

• Mincha gedola begins a half hour after noon 
• Mincha ketana begins two and a half hours before sunset
• One argument: the Mishna refers to mincha ketana because after mincha gedola there is still lots of time left in the day
• Another argument: the Mishna is referring to mincha gedola because each of the activities last a very long time, for example:

• getting the haircut that ben Elasa wore, where the hair was placed with the tips attaching to the roots of the hair
• the bathhouse can involve washing, washing hair, rinsing, sweating
• the tannery might be very large and the process of tanning take a long time
• one may not eat a big meal
• one may not begin judging a trial which might take a long time until a verdict is found

The rabbis go into further detail about each of these point.  Interestingly, we learn that the beginning of a meal might be marked by netilat yadaim, washing the hands.  Alternately it might be marked by when we loosen our belts.  I also like to mark the beginning of my meals with when I loosen my belt, so I'm going to choose to go with the opinion of Rabbi Chanina.