Bava Batra 56 - August 20, 16 Av

If there is no border, how does one determine how much of the field was acquired by the buyer? The sea quill was used by Yehoshua to demarcate borders between the tribes when they conquered the land of Israel. In the book of Yehoshua, some cities were listed but not others – why? The boundaries given to Moshe are those used to determine which land is obligated in tithes.  The ones excluded from this are the lands that belonged to other neighbors (not from the seven nations) - the Kini, Knizi and Kadmoni. There is a debate among three rabbis about where geographically these lands were. The Mishna and Gemara discuss issues regarding testimony for one who is trying to establish a three-year chazaka. Can three groups of witnesses testify each about a separate year? Is this considered a whole unit of testimony (which is acceptable) or a part of a testimony (which is not acceptable)?  If two witnesses testified about all three years but disagreed about which type of produce the person benefitted from, would their testimony be accepted?