Shiur Supplement - Daf 2a-b
A. Shenayim ochazin be-talit... ve-yachloku [lines 1-6] Two litigants appear before the court, holding on to a garment (talit). Each one claims sole ownership of the talit declaring that HE found it. The mishna rules that each must take an oath and, thereafter, the talit is divided equally between the two parties.
B. Lama li le-mitna....litni chada chada [lines 16-19] According to the mishna, each litigant makes TWO statements:
1. I found the object.
2. It belongs to me.
However, the mishna does not group the statements of each individual together. Rather it gives statement #1 of both litigants and THEN, statement #2 of both litigants. The gemara questions this unusual format and in the ensuing sugya, attempts to explain the reason behind this presentation.
C. De-i tana metzia... tzerikha [lines 1-10] According to R. Pappa (see the bottom of the previous amud) the mishna is formulated in such a way as it is dealing with two cases: The first, where two people argue over the ownership of a lost object, and the second, where the argument centers around who bought the disputed item from the shopkeeper. The gemara now explains why both cases needed to be taught in the mishna.
The basic assumption of the gemara at this point is that the shevu'a is administered in order to deter the litigant who is being deceitful. It is expected, that even tough he is trying to take money that doesn't really belong to him, he will not so far as to swear falsely. It should, furthermore, be noted that we do not suspect either party of being an outright thief. Rather we understand that sometimes a person may legitimise his actions - thinking that he is not doing so much wrong after all.
In the case of metzi'a we are concerned that the cheat will legitimise his actions by claiming that he is not really causing the other a loss. After all, he did not have to work or pay for a found object. On the other hand, in the case mekach, we are concerned that the thief will legitimise his actions as he too gave money to the shopkeeper and the other can go buy the item somewhere else.