Question: Indeed, he allows this l'Chatchilah!

Question #1 (Abaye - Mishnah #1 - R. Yishmael (some texts - R. Shimon)): Kohanim may eat Kodshim however they want, e.g. roasted, overcooked or cooked. They may mix in spices of Chulin or Terumah.

Answer (Rava): Terumah of spices is only mid'Rabanan, therefore, we are not concerned lest it becomes Pasul.

Question #2 (Abaye - Mishnah #2): We may not buy Terumah with money of Ma'aser Sheni, for this limits the consumption (Rashi - now, the Terumah must be eaten in Yerushalayim; Tosfos - now, only Kohanim may eat the Ma'aser);

R. Shimon permits this.

Rava could not answer.

Abaye reported this dialogue to Rav Yosef.

Rav Yosef: You could have asked from another Mishnah!

(Mishnah #3): We may not cook Shemitah vegetables in Terumah oil, lest the Terumah become Pasul.

R. Shimon permits this.

Abaye: I asked from Mishnah #1, and he answered that Terumah of spices is different, for it is only mid'Rabanan. He would answer Mishnah #3 similarly, that it discusses Terumah mid'Rabanan (Shitah Mekubetzes - e.g. sesame oil).

Rav Yosef: If Mishnah #3 discussed Terumah of vegetables (which is always mid'Rabanan) and Shemitah oil, you would be right. However, it discusses Terumah oil (which is usually from olives, which is mid'Oraisa) and Shemitah vegetables!

Abaye: Rabanan asked (end of 75b) from our Mishnah, and he answered that R. Shimon permits only if they already became mixed. He would answer Mishnah #3 similarly, that it discusses Terumah and Shemitah that were already mixed!

Objection (Rav Yosef): If they were already mixed, why do Chachamim forbid cooking them together? Do they equate this to an Asham mixed with a Shelamim?!

That is different, for there is a solution (Ro'im), therefore we do not cause Kodshim to be wasted. Here, in any case the Terumah must be eaten with the stringencies of Shemitah!

This case (Terumah mixed with Shemitah) is like a mixture of pieces of Kodshei Kodoshim and Kodshim Kalim. All agree that all must be eaten with the stringencies of the more stringent one!

Question (Ravina): A mixture of pieces of Kodshei Kodoshim and Kodshim Kalim is different, for there is no alternative. If Terumah oil was mixed with Shemitah vegetables, the oil can be squeezed out of the vegetables!

Answer: Rav Yosef holds that it is not feasible to squeeze out the oil;

If we squeeze out a lot (to get out all the oil), this will ruin the vegetables (and one may not ruin Shemitah produce);

If we squeeze out a little, some Terumah oil will remain, and it might become wasted (when Bi'ur comes)!

Question (Beraisa - R. Shimon): (A Nazir became Safek Tamei Mes. Additionally, he was a Metzora Muchlat (he was declared fully Tamei due to Tzara'as, and now it healed), but he is unsure if he must perform Taharas Metzora or if he already fulfilled it. He brings Tziporim (birds) today for the first step of Taharah. On day 30, he shaves all his hair.) The next day, he brings a (lamb for) Asham Metzora and a Log of oil, and stipulates:

If I need to bring Asham Metzora, this is the Asham and the oil that must be brought with it. If I need not bring it, this lamb is a Shelamim;

It must be slaughtered in the north (perhaps it is an Asham). Some of the blood must be put on his ear, thumb and toe (like Asham Metzora). It requires Semichah (some say that he does not do a proper Semichah, for Asham Metzora does not require Semichah mid'Oraisa, so he may not lean on the Korban), Nesachim (an accompanying flour and wine offering. Semichah and Nesachim are needed whether it is an Asham Metzora or Shelamim) and Tenufah (waving) of Chazeh v'Shok (the chest and thigh, in case it is a Shelamim);

It may be eaten for only one day and the following night (in case it is an Asham. Shelamim should be permitted for two days!)

Answer: (Normally, R. Shimon does not permit wasting Kodshim l'Chatchilah.) This is an exception. It is permitted for his Tikun. (There is no other way for him to become absolutely Tahor to eat Kodshim).

Question: This explains why we may offer the Asham. Why may we do (Safek) Avodah with the oil? Perhaps it is unnecessary, and this is Chulin b'Azarah!

Answer: He stipulates that if he does not need Taharas Metzora, the oil is Nedavah.

Question: If it is Nedavah, a Kometz must be taken!

Answer: Indeed, we take a Kometz.

Question: If he is a Metzora, seven Haza'os of oil are required!

Answer: We do seven Haza'os.

Question: [Since Kemitzah was taken,] a full Log does not remain!

Answer: We add more to restore the Shi'url

(Mishnah): If the Log is diminished before putting on the ear, thumb and toe, we add more to restore the Shi'ur.

Question: If it is Nedavah, we must burn the Kometz on the Mizbe'ach!

Answer: Indeed, we burn it.

Question: When do we burn it?

If this is after the Haza'os, some of the Shirayim (leftovers) after Kemitzah are missing before Haktarah. Haktarah is forbidden in such a case!

Version #1 (Rashi): If this is before the Haza'os, this forbids doing Haza'ah, for (Haza'ah is like Haktarah, and) "Lo Saktiru" (do not burn) applies to Shirayim of anything that is partially burned on the Mizbe'ach!

Version #2 (Tosfos): (Even) before the Haza'os, we may not burn the Kometz. Since we will do Haza'os, the oil is like a Korban, and "Lo Saktiru" applies to it (according to R. Akiva). (end of Version #2)

Answer (Rav Yehudah brei d'R. Shimon ben Pazi): He burns it, and stipulates that if this is unnecessary, it is l'Shem Etzim (like burning wood on the Mizbe'ach, i.e. not an obligatory Avodah. Rashi - this means that he sprinkles with intent 'if this is unnecessary, this is like sprinkling water.')

(Beraisa - R. Eliezer): "L'Re'ach Nicho'ach" - you may not offer (Chametz or honey (i.e. any sweet derivative of fruit) on the Mizbe'ach) to fulfill Hash-m's will, but they may be burned l'Shem Etzim.