Study Guide Bava Kamma 50 Today's daf is sponsored by Shira and Dori Dishon in loving memory of their son, Eitan Dishon, who heroically fought in Gaza. "He loved learning Torah and encourage his father to learn daf yomi with him. We will b'ezrat Hashem complete that for him." Rabbi Akiva and Rabbi Yishmael debate what the classic case of bor is - in public property or in private property that was made public but the owner retains ownership of the bor. Raba and Rav Yosef each hold that Rabbi Akiva and Rabbi Yishmael agree about the law in one case (public/private) and disagree about the other. Raba holds that they agree about public property and Rav Yosef holds the opposite. Rav Yosef's opinion is questioned by two braitot but they are resolved. A story is brought about a reservoir digger, Nehunia ben haKane, who dug cisterns for public use and whose daughter fell into a pit and was saved. A theological statement is made about why she never would have died in that way because of her father's actions. However, Rav Acha points out that his son died from thirst, even though his father had dug the cisterns so people would have water to drink on the way to Jerusalem for the holidays. He explains that God is particular with righteous people in a very exacting manner. What is the source of this? One should not remove stones from their property and place them in the public domain. Rav and Shmuel argue about whether one is responsible for bor because the fumes of the bor can kill/injure or also because of the impact of the hit on the floor of the bor. Two sources are brought to raise a difficulty with Rav's position (fumes). Within the response to the first difficulty, the Gemara explains why the Mishna needed to bring a long list of different types of items that fall under the category of bor - what is unique about each one?