1) WERE THE "ZIKNEI DAROM" TANA'IM OR AMORA'IM?
OPINIONS: The Gemara records the novel opinion of the Ziknei Darom, who rule that when one is Tamei Mes he is permitted to send all types of Korbanos to the Beis ha'Mikdash, including the Korban Pesach, according to the letter of the law.
The Gemara asks numerous questions on their opinion. One of its questions is from a Beraisa which derives from the verse, "b'Michsas Nefashos" -- "for specifically designated individuals" (Shemos 12:4), that the Korban Pesach may be slaughtered only for a person who is included in the designated group which is bringing the Korban Pesach. If it is slaughtered for someone who is not part of the group, it is Pasul. This is the case not only with regard to slaughtering the Korban for a person who is not part of the group, but even for a person who is Tamei Mes. The Beraisa explicitly compares the law of slaughtering for a person who is not part of the group to the law of slaughtering for a person who is Tamei Mes. How do the Ziknei Darom understand this Beraisa? The Gemara answers that they simply do not compare the two laws, and therefore they understand that a Tamei Mes may send his Korban Pesach according to the letter of the law.
How can the Ziknei Darom argue with the Beraisa? Are they Tana'im? The Gemara earlier (22b) implies that they are not Tana'im, because it quotes them in the context of a dispute with Reish Lakish, an Amora.
(a) TOSFOS (DH Ziknei Darom) explains that the Ziknei Darom indeed are Tana'im, and they may argue with the Beraisa. This also explains why they may argue with an explicit Mishnah in Pesachim (61a) which says that when one slaughters a Korban for people who are Tamei Mes, the Korban is Pasul.
If the Ziknei Darom are Tana'im, then how can Reish Lakish argue with them? Perhaps Tosfos had the text of the HAGAHOS HA'BACH (22b) which replaces "Reish Lakish" with "Reish Galusa." Alternatively, perhaps Reish Lakish relies on the Beraisa quoted by the Gemara here which clearly argues with the Ziknei Darom.
(b) Alternatively, Tosfos says the Ziknei Darom follow one version of the opinion of the Tana, Rebbi Nasan (Pesachim 78b), who says that one does not have to eat the Korban Pesach in order to be able to send a Korban Pesach. Tosfos apparently means that the Ziknei Darom were Amora'im, but since they have a Tana on whom to rely, they are able to argue with the Beraisa.
The MAGINEI SHLOMO in Pesachim (69b) proves from the fact that Reish Lakish argues with the Ziknei Darom that they must be Amora'im. Although he agrees that one could refute this proof by saying that Reish Lakish lived during the era of the last Tana'im, he concludes that this is not a good answer in the case of the Ziknei Darom. Tosfos himself states that the Ziknei Darom clearly argue with an explicit Mishnah. If they are Tana'im, why does the Gemara ask numerous questions on them from Beraisos, when it is clear that they argue on an explicit Mishnah? It must be that they are Amora'im who were able to learn the Mishnah in Pesachim differently. (See the Maginei Shlomo, who says that the Ziknei Darom follow the view of Rebbi Eliezer in Pesachim 69b, and not that of Rebbi Nasan.) (Y. MONTROSE)
2) IS A KOHEN WHO SITS WHILE PERFORMING THE AVODAH "CHAYAV MISAH"?
OPINIONS: The Mishnah (15b) states that when a Kohen is Mekabel the blood of a Korban while seated, the Avodah is Pasul. Rava derives this from the verse, "la'Amod l'Shares" -- "to stand to serve" (Devarim 18:5). Rava explains that the verse teaches that when the Kohen is standing, he is considered "chosen for Kehunah." When he is sitting, he is not considered "chosen for Kehunah."
After Rava derives this law from the verse, he asks Rav Nachman why the Halachah is that a Kohen who sits while he performs the Avodah is not Chayav Misah. Just as a Zar who performs the Avodah is Chayav Misah, a Kohen who sits while he performs the Avodah should be Chayav Misah.
Why does Rava consider the possibility that a Kohen who sits while performing the Avodah is Chayav Misah? On what basis does he compare a Kohen who is sitting to a Zar?
(a) RASHI (DH Eima Mah Zar) says that Rava asks that perhaps a Meh Matzinu teaches that just as the Avodah performed by a Zar is Pasul and the Zar is Chayav Misah, the Avodah performed by a Kohen while he sits is Pasul and the Kohen is Chayav Misah.
TOSFOS (DH Eima) questions this explanation. The Mishnah also states that any Avodah performed by a Kohen who does not have a Bris Milah, or by a Kohen who is an Onen, is Pasul. Rava, however, does not ask whether those Kohanim are also Chayav Misah, as he asks in the case of a Kohen who sits while he performs Avodah. According to Rashi's explanation, the same question should apply in those cases.
(b) Tosfos explains that Rava's question is based on the fact that a Kohen who performs the Avodah while he sitting is like a Zar. Accordingly, he should receive the same punishment as a Zar. This question does not apply to a Kohen who does not have a Bris Milah or to an Onen, because the reason why their Avodah is Pasul is not because they have the status of a Zar.
How, though, does Rashi answer the question of Tosfos?
The SHITAH MEKUBETZES answers that Rava indeed could have asked his question in the case of a Kohen who does not have a Bris Milah, and in the case of an Onen, but he chose to ask his question in only one of the cases (a Kohen who performs the Avodah while sitting). (The SEFER EIZEHU MEKOMAN quotes other texts of Rashi, which read that the law that a Kohen who sits while he performs the Avodah makes the Avodah Pasul is an independent law and is not due to the Kohen having the status of a Zar. Based on those texts, Rashi could not have learned the Gemara like Tosfos.) (Y. MONTROSE)