As we learned on yesterday’s daf many of the activities associated with bringing the korban minḥa – a meal offering – are required ab initio, but after the fact the offering would be valid even if these activities are not performed correctly. This is derived from the repetition of certain of the laws of korban minḥa in the Torah.
One of the examples in the Mishna of this rule is the need to salt the meal offering before placing it on the altar. Since salt is not repeated, the tanna of the Mishna does not deem it an essential part of the minḥa offering.
The Gemara on today’s daf points out that this ruling regarding salt and the korban minḥa is not agreed upon by all. A baraita is quoted where we find that Rabbi Yehuda understands a passage in the Torah to require that all sacrifices be brought with salt (according to the reading in our Gemara, the passage in question is from Sefer Bamidbar 18:19. Rabbeinu Tam in Tosafot argues that that passage does not relate to sacrifices, and suggests an alternative reading, which has Rabbi Yehuda’s source as 2:13, where it clearly states that the covenant of salt should never be left out when bringing sacrifices). The baraita also offers the opinion of Rabbi Shimon who learns this rule from the parallel covenantal language found in 18:19 regarding salt and in 25:12 regarding kohanim. Rabbi Shimon argues that just as sacrifices cannot be brought without kohanim, similarly they cannot be brought without salt.
Rashi understands that there is no real difference between Rabbi Yehuda and Rabbi Shimon; they simply derive the same law requiring salt on all sacrifices from different biblical passages. The Kesef Mishna argues that according to the Rambam there are differences between them. He suggests that according to Rabbi Yehuda only meal offerings require salt, while Rabbi Shimon rules that this law applies to all sacrifices. In his Meshekh Ḥokhmah, Rabbi Meir Simḥah HaCohen of Dvinsk suggests that they differ in a case where a meal offering is brought on a bama – a private altar – at a time that it was permissible to do so. In such a case Rabbi Yehuda would still require salt; Rabbi Shimon would argue that since we do not need kohanim to perform the service on a private altar, we do not need salt, either.