1) IS THE SPILLING OF THE "SHIRAYIM" "ME'AKEV"?
OPINIONS: Rav Ada bar Ahavah says that Rebbi Yishmael and Rebbi Akiva disagree about whether or not Shirayim are Me'akev. Rebbi Yishmael maintains that the Shirayim are Me'akev, while Rebbi Akiva maintains that they are not. Does this mean that Rebbi Yishmael maintains that if the Kohen does not spill the Shirayim on the Yesod that the Korban is Pasul?
(a) The OLAS SHLOMO understands that this indeed is the view of Rebbi Yishmael. He explains that according to Rebbi Yishmael, the ability of the Zerikah to effect the atonement of the Korban depends on whether the Shirayim are spilled on the Yesod. If the Shirayim are not spilled on the Yesod, the Zerikah does not atone. RAV ARYEH LEIB MALIN (23:2) seems to have a similar understanding of the Gemara.
(b) The MEKOR BARUCH (1:12) understands that the Tana'im disagree not about whether the Korban is valid, but about whether one fulfills or fails to fulfill the Mitzvah of Shirayim.
(c) The YAD BINYAMIN quotes many Acharonim who similarly understand that the disagreement involves whether one is obligated to leave blood over in order to spill Shirayim on the Yesod. According to Rebbi Yishmael, one is obligated to leave some blood over. According to Rebbi Akiva, one is not obligated to leave blood over in order to spill it on the Yesod; if there happens to be blood left over, then there is a Mitzvah to pour it on the Yesod. (See TOSFOS to 53b, DH ha'Olah, who implies that this is a subject of dispute among the Ba'alei ha'Tosfos.) (Y. MONTROSE)
2) KORBANOS WHICH NEED "ZERIKAH" ABOVE OR BELOW THE "CHUT HA'SIKRA"
OPINIONS: Different types of Zerikah are done with different types of Korbanos. Some Korbanos require that four different sprinklings be done with their blood, and some require only one. The Gemara here quotes a Beraisa which states that if a Korban was supposed to have four sprinklings but only one was done, it is valid b'Di'eved. The Beraisa continues and suggests that, similarly, if the Zerikah of a Korban was supposed to be done above the Chut ha'Sikra but it was done below the Chut ha'Sikra, it should be valid b'Di'eved. However, the Beraisa derives from a Gezeirah Shavah that this is not the case. The Torah uses the word "Damim" with regard to both types of Korbanos (the Korban which needs Zerikah above the Chut ha'Sikra, and the Korban which needs it below). The Gezeirah Shavah teaches that just as a Korban which needs Zerikah below the Chut ha'Sikra is Pasul if the Zerikah is done above the Chut ha'Sikra, a Korban which needs Zerikah above the Chut ha'Sikra is Pasul if the Zerikah is done below the Chut ha'Sikra.
What specific Korbanos is the Gemara discussing?
(a) RASHI (DH Ne'emru and v'Ne'emar) explains that the Korban which needs Zerikah below the Chut ha'Sikra is a Chatas ha'Of, while the Korban which needs Zerikah above the Chut ha'Sikra is a Chatas Behemah. Rashi (DH Mah Damim) explains that the verse which discusses Chatas ha'Of says, "Chatas Hi" -- "it is a Chatas" (Vayikra 5:11), teaching that the blood of the Chatas ha'Of must be placed below the Chut ha'Sikra.
TOSFOS (DH Mah Damim) has difficulty with Rashi's explanation. How do the words "Chatas Hi" imply that the Zerikah must be done only in the place specified by the Torah? When the Torah discusses the Chatas Behemah, it also says an extra word "Hi": "Kodesh Kodashim Hi." According to Rashi's logic, why is it necessary to compare Chatas Behemah to Chatas ha'Of in order to teach that the Zerikah of a Chatas Behemah may be done only above the Chut ha'Sikra? This can be derived from the extra word of "Hi" written with regard to Chatas Behemah!
The SHITAH MEKUBETZES is also bothered by this question, and he asks another question on Rashi's explanation. According to Rashi, the train of thought of the Beraisa is unclear. Does it follow that once we know that a Korban which is supposed to have four sprinklings is valid b'Di'eved if only one sprinkling is done, that a Korban which needs Zerikah above the Chut ha'Sikra is valid b'Di'eved if Zerikah is done below the Chut ha'Sikra? What does one have to do with the other?
(b) The Shitah Mekubetzes quotes the RI who explains the flow of the Beraisa. The Beraisa first says that a verse teaches that the Zerikah (of a Chatas Behemah) must be done above the Chut ha'Sikra. The Beraisa then asks, why would one have thought otherwise? It answers that since the verse says, "v'Dam Zevachecha Yishafech" -- "and the blood of your offerings you shall pour [on the Yesod]" (Devarim 12:27), one might have inferred that this refers not only to leftover blood, but that any blood spilled on the lower part of the Mizbe'ach is considered a valid Zerikah (see Shitah Mekubetzes at length for how the verse implies specifically the lower part of the Mizbe'ach). The Beraisa then says that this is not a good enough reason to require a verse in the case of Chatas Behemah to teach that the Zerikah is Pasul if done below the Chut ha'Sikra, since it can be derived from Chatas ha'Of. Just as the Zerikah of a Chatas ha'Of is Pasul if done on the upper half of the Mizbe'ach (since there is no indication in the verse that it is valid), the Zerikah of a Chatas Behemah should be Pasul if done on the bottom half of the Mizbe'ach.
In addition to his explanation of the flow of the Beraisa, the Ri points out that the derivation from Chatas ha'Of would not because of a Gezeiras ha'Kasuv of "Hi," which would also apply to Chatas Behemah, but rather it is based on logical grounds.
How does Rashi answer the question of the Shitah Mekubetzes, that the Torah also writes an extra word "Hi" with regard to Chatas Behemah?
The Shitah Mekubetzes quotes his Rebbi who answers that the word "Hi" in the verse of a Chatas Behemah appears before the Torah discusses the Zerikah of the Chatas Behemah. Accordingly, there is no reason to assume that the verse is teaching a Halachah of a Chatas Behemah unique to Zerikah. In contrast, the words "Chatas Hi" in the verse of a Chatas ha'Of indeed appears after mention of the Zerikah. Therefore, it indeed could be teaching a Halachah about the Zerikah.
This answer is also given by the PANIM ME'IROS and the TZON KODASHIM. The Tzon Kodashim points out that this question indeed was anticipated and answered by Rashi, who writes (DH l'Matah), "d'Ha Kesiv b'Haza'aso Chatas Hi" -- "that it is written with regard to its Haza'ah (i.e. the Haza'ah of the Chatas ha'Of) 'Chatas Hi'." (Y. MONTROSE)