Menakhot 9 Tosefot highlights a weak proof

Three times on today’s daf TB Menakhot 9 Rabbi Yoḥanan and Reish Lakish find themselves on opposite sides of a disagreement. One of these disagreements concerns whether you’re allowed to mix the oil in the minkha offering outside the walls of the Temple courtyard. The mixing of the oil and the flour was a three-step process. Yetzika (יצִיקה)-the oil was placed at the very bottom of the bowl. Then the fine flour was added on top of it. Belilah (בְּלִילָה)-oil was placed on top of the flour and then it was mixed together.

“It was stated: If one mixed the oil of a meal offering into it outside the wall of the Temple courtyard, Rabbi Yoḥanan says that it is disqualified, and Reish Lakish says that it is valid. Reish Lakish says: It is valid, as it is written: “And he shall pour oil upon it, and put frankincense upon it” (Leviticus 2:1), and then it is written: “And he shall bring it to Aaron’s sons the priests; and he shall remove” (Leviticus 2:2).

“Reish Lakish explains: The Sages derived from here that from the removal of the handful onward the rites performed with the meal offering are solely a mitzva of the priesthood. Accordingly, the verse taught about pouring and mixing that they are valid when performed by a non-priest. And from the fact that the priesthood is not required for the mixing, it may be derived that it is also not required that its performance be inside the walls of the Temple courtyard.” (Sefaria.org translation)

Tosefot ד"ה וּמִדִכְהוּנָה notices that Reish Lakish’s argument is not a very strong one. One cannot draw the conclusion that just because a non-priest may do the mixing doesn’t mean the mixing can be done outside the Temple courtyard. A non-priest may slaughter the animal sacrifice (shekhita-שְׁחִיטָה), but it has to take place within the walls of the temple courtyard.

Tosefot provides two solutions. Conceptually shekhita may be permitted outside the Temple courtyard, but practically it is impossible for the following reason. Only a kohen may capture the blood spurting forth from the neck of the animal in a bowl and bring it to the altar. For obvious reasons, this has to be done immediately after the animal is slaughtered and within the Temple courtyard. Their second solution is already recorded earlier in the Gemara. Animal sacrifices are inherently different than minkha offerings. One cannot necessarily learn a law from each other.

As always, the halakha follows Rabbi Yoḥanan over Reish Lakish. See Rambam’s Mishneh Torah, Sefer  Avodah, Sacrifices Rendered Unfit, Chapter 11, Halakha 6.