Eiruvin 51a, b

The rabbis again focus on the establishment of an eruv through intention and/or statement.  In 51a, the Gemara asks how two thousand cubit came to be understood as the home boundary, the "place" as defined by the Shabbat limit.  The Gemara then explains that two statements in Exodus 16:29 foretell this arrangement.  The Torah says that every person should stay in their place, and that no person should leave their place.  One of these refers to two thousand cubits, and the other refers to four cubits.  Interesting. 

The rabbis go on to explain why 2000 cubits was chosen as the area of one's "place".  Apparently the Levite cities and then the cities of refuge (set aside for those who had committed a crime and were removed from society) were 2000 cubits as defined by Torah law.  Thus the rabbis felt justified in choosing this same area as that of Shabbat's "place".

The rabbis discuss different opinions regarding the 2000 cubit area and the actual distance that one can carry within a four cubit radius.  Rabbis argue that the area is circular and that the area is square.  Mathematical formula are used to demonstrate their ideas.  Some rabbis believe that one can carry a four cubit line from where s/he is situated on Shabbat.  Others believe that s/he can carry on the diagonal line, as if s/he were beginning her/his carrying from the diagonal point in a four cubit square.  All of these opinions are debated and proven.

Finally, 51b focuses on the fact that a wealthy person and a pauper are both allowed to set the eruv by foot.  The rabbis discuss whether this includes the intention to establish a residence, the statement that one is establishing a residence, actually arriving at that 'residence' before the beginning of Shabbat, or having the ability to arrive at that stated residence before the start of Shabbat.  The rabbis discuss reasoning, including whether or not one can afford two meals, whether or not one has bread enough to establish an eruv, and other factors.

When the Torah says something in two different ways, one immediately next to the other, the rabbis argue that there must be meaning behind that word placement.  It could not be a literary device, or a way to accentuate a point.  Instead we are to look for the deeper meaning behind those consecutive sentences.

I have found that Torah study - while very meaningful and emotionally evocative - is not primarily an emotional task.  I do not learn Torah because it makes me feel close to G-d.  To do that, I pray, or meditate, or walk in the woods.  I learn Torah because it is inherently an intellectual exercise while it connects .  Our Sages created rules that help me to stretch my brain and twist words until I can understand them better; feeling connected to my ancestors at the same time.  Daf 51a reminds me that as I learn every day, I am consciously and unconsciously participating in that tradition of reasoning and struggling and questioning.