Although the main discussion of the laws regarding lost and found objects appears in the second perek of Massekhet Bava Metzia – Elu Metzi’ot – the first perek, which begins on our daf focuses on one specific subset of that question – shenayim ohazin be-talit – a case where two people are claiming ownership of the same cloak that they found. At first glance, this appears to be a discussion of a side topic, and it seems odd to place a secondary issue before the primary one. Nevertheless, the conclusions that are reached based on the clarification of this issue helps us understand a range of basic rules in a number of areas – e.g. how to define “possession” and how it is established, under what circumstances possession will lead to ownership. Furthermore, we get to clarify the question of how a court establishes rights and ownership when faced with competing claims on a single object.
The rishonim offer other explanations for placing the Mishna of shenayim ohazin be-talit at the very beginning of Massekhet Bava Metzia. According to Tosafot, since this tractate is essentially the middle part of a larger one – Massekhet Nezikin, which deals with issues of civil law, and was eventually divided into three parts – the opening Mishna is simply a continuation of the last topics that were discussed in Massekhet Bava Kamma, whose focus was how to divide property between different claimants based on oaths that they were forced to take in court. In his responsa, the Rashbatz – Rabbi Shimon ben Tzemah Duran – suggests that it is not unusual for us to find that the Sages of the Mishna chose to first examine topics in which they found particular interest or some ḥidush (a new and different idea), placing them before more basic issues that need to be discussed.