Right before the mishnah we see that Rav Shimi refutes the fact that there is kofer by regel by learning the kal vachomer from nezikin of regel and not by kofer of regel. From that point on until the Mishnah is very confusing. If you would be able to give me a basic pshat in those lines of Gemara (incorporating Rashi if possible) then it would be great. Yeshar Koach!
Moshe Sasson, New York,USA
Here are my notes taken from 'Questions and Answers' on the Masechta. See if they help you understand the Sugya. If they don't, I will go through the Sugya for you with Rashi (b.n.)
(a) Rav Shimi from Neherda'a tries to refute this proof. He claims that it is not from a 'Kal va'Chomer' from Regel that Rebbi Tarfon learns that Keren pays full damages for Kofer in the Reshus ha'Nizak - but from the same 'Kal va'Chomer' from Nizakin of Regel.
(b) We refute Rav Shimi's proposal to learn the Din of Kofer from Nizakin of ...
1. ... Regel - because Nizakin pertains also to Eish (which Kofer does not).
2. ... Tamun be'Regel (which is exempt by Eish) - because it pertains to Bor (which Kofer does not).
3. ... Keilim (which are exempt by Bor) - because it pertains to fire (which Kofer does not).
4. ... Keilim Temunim (which are exempt by Bor) - because they pertain to Adam (which Kofer does not).
(c) So we conclude that Rebbi Tarfon can only have learned his Din from Kofer of Regel. Rav Acha mi'Difta proves that in any event, he must hold 'Yesh Kofer be'Regel. This because, had he held 'Ein Kofer be'Regel', and learned his Din from Nezikin de'Regel - we could have asked how we can possibly learn Kofer of Keren (in the Reshus ha'Nizak) from Nezikin of Regel, seeing as Keren has the Chumra of Kofer, which Regel does not have.
Wishing you a Kesivah va'Chasimah Tovah.
Eliezer Chrysler