1) A PUBLIC PATH THAT BECOMES LOST
QUESTION: The Mishnah discusses a case in which the public has the right to use part of a person's field as a path. The RASHBAM (DH Mi she'Haisah) explains how the public obtained the right to the path: either the public always used the area as a path, or an owner of the field gave the public explicit permission to the public to use it as a path. However, the present owner now wants his field back. To that end, he designates a different area at the side of the field as a path for the public's use, and he takes back the land used as the path in the middle of his field. The Mishnah states that the public has the right to the new path, and the public still may use the old path as well.
The Gemara asks why the fieldowner cannot simply take back the path with the claim that he gave it to the public by mistake? Rebbi Eliezer answers that the public has the right to choose whatever property it wants. The Gemara questions this statement. Can the public really go and usurp property indiscriminately? Rav Gidal in the name of Rav explains that the public may make claim to a piece of property only when the public already had the right to an area in that property but there is now a doubt about the exact location of that area. In such a case, the public may choose their path in the field without having to go to Beis Din.
The Gemara asks that this implies that the Halachah follows the view of Rebbi Eliezer, since the Mishnah is in accordance with his opinion. However, Rabah bar Rav Huna in the name of Rav explicitly states that the Halachah does not follow the view of Rebbi Eliezer. The Gemara answers that Rabah bar Rav Huna and Rav Gidal disagree about the position of Rav.
According to Rabah bar Rav Huna, what is the reasoning of the Mishnah? The Gemara explains that Rabah bar Rav Huna clearly follows the reason given by Rebbi Yehudah, that once the public walks on a path given to them by a fieldowner they acquire it, and the fieldowner no longer may take it back.
The Gemara's original answer does not seem consistent with the Mishnah. Even if the public originally had a path in the field, such that if the path becomes lost the public may choose a new path in the field, in the case of the Mishnah the fieldowner gives the public a new path outside of his field, where the public had no path previously. How are the two cases related?
ANSWERS:
(a) The RASHBAM (DH keshe'Avdah) explains that the Gemara is making a Kal va'Chomer: If the public is permitted to choose a new path when they lose their old path which the fieldowner let them use (i.e. he did not protest), then certainly where a fieldowner originally gave them the use of the field, they may use the path.
TOSFOS (DH Kegon) has a number of difficulties with this approach. The Gemara in Bava Kama (28a) discusses the Mishnah, but it cites only Rebbi Yehudah's reason and not Rebbi Eliezer's reason. This implies that everyone agrees with the reason that Rebbi Yehudah gives for the Mishnah. Why does the Gemara there leave out the reason of Rebbi Eliezer?
Moreover, what is the Kal va'Chomer from the case of Rebbi Eliezer? In his case, the public definitely owned a path, and the only question is where the path is situated. In the case of the Mishnah, the public never had any claim to the path at all; it merely was given to them by mistake by the fieldowner. Why should the ruling of Rebbi Eliezer teach anything about the case in the Mishnah?
(b) TOSFOS quotes the RI who explains the Gemara in an entirely different manner. The Gemara cites Rebbi Eliezer's words in order to explain the Mishnah. Rav Gidal, however, quotes Rav who says that Rebbi Eliezer's words do not explain the Mishnah. Rebbi Eliezer did not say that the public may do whatever it wants (which would explain the Mishnah), but that only when the public already had a path in the field but it became lost may the public claim a new path anywhere in the field. Accordingly, the Mishnah is unrelated to Rebbi Eliezer's statement; the Mishnah does not discuss a path which the public lost, but rather a path which the owner mistakenly gave to the public.
Once the Gemara mentions Rebbi Eliezer, it asks that if Rebbi Eliezer's words were said in the case as explained by Rav Gidal, why would Rabah bar Rav Huna say that Rav does not rule like Rebbi Eliezer? Why should Rebbi Eliezer's opinion not be the Halachah? The RITVA explains that although the Gemara in Kesuvos (109b) says that in such a case an individual would have to go to Beis Din to sort out the exact location of his lost path, the public should have a stronger right than that of an individual (at least b'Di'eved). The Gemara answers that it must be that Rabah bar Rav Huna understands that Rebbi Eliezer's statement was said not in a case in which the pubic lost a path, but in a case in which the public seized a path. Therefore, he says that the Halachah does not follow the view of Rebbi Eliezer. The Gemara continues to discuss the reasoning of the Mishnah, and it says that the reasoning of the Mishnah is the reasoning of Rebbi Yehudah. This is why the Gemara in Bava Kama (28a) does not mention any other reason for the Mishnah's ruling. (Y. Montrose)

100b----------------------------------------100b

2) SITTING AND STANDING AFTER ONE LEAVES THE CEMETERY
OPINIONS: The Gemara says that after a burial, the people who leave the cemetery should stop no less than seven times, at which they sit down and rise again and continue to walk. This ritual corresponds to the verse, "Havel Havalim, Amar Koheles, Havel Havalim ha'Kol Havel" -- "'Vanity of vanities,' said Koheles, 'Vanity of vanities, all is vanity'" (Koheles 1:2). (The Gemara counts seven occurrences of the word "vanity" in this verse, since each plural word ("vanities") is regarded as two.)
What exactly is the connection between this verse and the ritual of sitting and standing seven times?
Moreover, do the people merely sit and stand when they perform this ritual, or do they do something else?
(a) The RASHBAM (DH mi'Shiv'ah) explains that the people walk a little and then sit down in order to comfort the mourner, and in order to lament the loss of the departed, and in order that each person take to heart that he, too, will die one day and thus he should do Teshuvah now. The Rashbam explains that the Gemara derives this from the seven mentions of "vanity" in the verse in Koheles. The verse there emphasizes how the pleasures of this world are meaningless since everyone ultimately dies.
(b) The Rashbam records another explanation which he read. According to that explanation, Shedim (demons) follow people back from the cemetery. In order to make the Shedim leave, the people delay their return by first sitting and standing for a while. After they have done this seven times, the Shedim leave the people alone. This explanation is also stated by the TESHUVOS MAHARIL (#23).
The Rashbam does not accept this explanation. If this is the reason for the ritual of stopping seven times, then it should be done in any place where there are Shedim, and not only in a cemetery. Moreover, this reason is unrelated to the verse of "Havel Havalim."
(c) The RITVA explains that the seven times the people sit and stand symbolize the seven cycles of the year mentioned in the verse, "Zera v'Katzir v'Kor va'Chom v'Kayitz va'Choref Yom va'Lailah" -- "seed time and harvest, and cold and heat, and summer and winter, and day and night shall not cease" (Bereishis 8:22). ("Day and night" represent one season, as the verse calls them "Yom Echad" -- "one day," in Bereishis 1:5.)
(Perhaps the Ritva does not mention that the seven times are derived from the seven Havalim in the verse in Koheles, since not all seven Havalim are mentioned explicitly in the verse.) (Y. Montrose)