1) WAS RAV KAHANA A KOHEN?
OPINIONS: The Gemara relates that Moshe Rabeinu passed down a teaching that a person (such as one who teaches Torah) should do work that is foreign to him instead of having to accept Tzedakah. The Gemara says that this is similar to what Rav told Rav Kahana. Rav told Rav Kahana that it is better to carry an animal carcass in the marketplace and be paid for it than to say that "I am a great man and the work is undignified for me."
A slightly different conclusion to Rav's statement is printed in some texts of the Gemara. According to those texts, Rav told Rav Kahana that it is better to carry an animal carcass in the marketplace and be paid for it than to say that "I am a Kohen (Kahana Ana) and the work is undignified for me." Which text is more accurate?
(a) The RASHBAM (DH v'Lo Teima) says that the correct text is the one that appears in our Gemara.
(b) It is clear from TOSFOS (DH v'Lo Teima) that his Gemara had the second text. RABEINU TAM understands that the words "Kahana Ana" do not mean "I am a Kohen." Rather, Rav told Rav Kahana that he should do demeaning work rather than say "I am Rav Kahana and this work is undignified for me." Rabeinu Tam explains that Rav would not have told Rav Kahana not to say that he was a Kohen, because Rav Kahana was not a Kohen. This is apparent from the Gemara in Chulin (132a), which teaches that a person may give the Matnos Kehunah of the Zero'a, Lechayayim, and Keivah to a Bas Kohen, even if she is married to a Yisrael. The Gemara proves this from the conduct of Rav Kahana, who ate Matnos Kehunah because of his wife who was a Bas Kohen.
(c) The RITVA also quotes the second text, but he understands that "Kahana Ana" means that one should not say "I am a Kohen" (as the Rashbam understands that text). Why would Rav tell Rav Kahana not to say "I am a Kohen" if Rav Kahana was not a Kohen, as Rabeinu Tam proves from the Gemara in Chulin? The Ritva answers that there may have been two Amora'im named Rav Kahana, one of whom indeed was a Kohen.
(d) Alternatively, the Ritva explains that the words "Kahana Ana" -- "I am a Kohen" -- also mean that "I am a dignified person" and do not necessarily mean that the person is a Kohen.
(e) The Ritva suggests a third explanation. Rav was not telling Rav Kahana what he personally should not say to avoid working. Rather, he was telling him that a person in general should not try to get out of working, for example by saying that he is a Kohen. (Y. MONTROSE)
2) WHY ONE WOULD THINK THAT A DAUGHTER IS LIKE A SON
OPINIONS: The Gemara earlier (110a) derives from the verse, "When a man dies and he has no son, you shall pass his inheritance to his daughter" (Bamidbar 27:8), that if the man who died does have a son, that son receives the entire inheritance. The Gemara here asks that perhaps the Torah merely means to teach that a daughter inherits? The Gemara answers that this is already learned from the verse of "v'Chol Bas Yoreshes Nachalah" -- "And every daughter who inherits her father's estate..." (Bamidbar 36:8).
What exactly is the Gemara's challenge and its answer?
(a) The RASHBAM (DH Amar Lei Rav Papa) explains that his teachers gave the following explanation of the question. Perhaps the reason why the Torah does not state explicitly that a daughter inherits just as a son inherits is that one might have thought that a daughter inherits only when there is also a son, but when she has no brothers perhaps the inheritance is passed on to a different relative. This is why the Torah writes that if there is no son, then a daughter inherits. The Torah teaches that she certainly inherits when she has no brother.
(b) The Rashbam gives another explanation of the Gemara's question, which is the opposite of his first explanation. The fact that a daughter is mentioned at all in the Parshah of Yerushah is a novelty, since all of the other people mentioned in the Parshah are males. Moreover, the Gemara earlier (109b) derives from the verse (Bamidbar 1:2) "l'Mishpechosam l'Veis Avosam" that only the family of the father is considered family in matters of inheritance. It is possible, therefore, that although the verse says that a daughter inherits, it may mean that when there is no son, the daughter inherits in such a way that her husband and son effectively receive the inheritance, unless she inherits with her brother, in which case some of the inheritance is not passed on to others since it stays with the son (as opposed to the part that goes from the daughter to her husband or son from another Shevet).
(c) The SHITAH MEKUBETZES quotes the RE'EM who says that the verse of "Ish Ki Yamus" (Bamidbar 27:8) may be understood in a different manner. The Torah may be teaching that a daughter receives a full inheritance when she does not have a brother, which implies that she receives only half when she has a brother. (Y. MONTROSE)