Nusach Ashkenaz says Shalom Rav at Mincha most days. However, when there is Birchas Kohanim (such as a fast day), they say Sim Shalom. Is there a connection between Birchas Kohanim and Sim Shalom? If there is a connection, what is it?
According to the Rambam Hil. Tefillah 1:2, Tefillah ends with hoda'ah, gratitude, not a request to grant peace. Bakashos, requests, are in the middle of the tefillah.
My Rav gave a shiur based on the above, plus the idea of bircas kohanim following avodah (Shmini 9:22) (and other sources), that sim shalom is a distinct part of tefillah specially instituted as a format for saying bircas kohanim. In other words, sim shalom exists only to say bircas kohanim.
However, it was instituted as an integral part of shemona esre and is said even in the silent tefilla and even when there are no kohanim or where the minhag is not to say bircas hakohanim. I don't know how the nusach change was established.
I recently got a ksav yad of the shiur from my rav. I can't post the entire shiur, but the upshot is as follows:
- The bracha of shalom rav is a public bracha (tzorchei rabim) as the language testifies. Its proper place is before modim (which completes the tefilah) as part of the final 3 brachos, as it is tzorchei rabim.
- Bircas kohanim is an independent institution that the sages structured following the tefilah (but as part of the tefilah) in the same way it followed avodah in the mikdash.
- Bircas kohanim should be followed with a bracha for the individual (tzorchei yachid) asking that the brachos should be accepted on us. This must be done specifically after bircas kohanim.
- The bracha of shalom and the bracha for acceptance are combined into sim shalom when bircas kohanim should be said. This is why sim shalom is in a language of tzochei yachid (borcheinu- like choneinu, refaeinu). Because part of the dual nature of the bracha is for bircas kohanim, the bracha must be said after bircas kohanim, not before modim.
- To avoid confusion, the sages instituted shalom rav after modim as well.
Textual variants other than Nusach Ashkenaz simply have the text sim shalom.
In Nusach Ashkenaz, it appears that the lengthy sim shalom was intended for prayers at which Birkat Kohanim (which concludes with "may G-d grant you peace") could be said; and an abridged version, shalom rav, at prayers where it couldn't. (At night, as well as afternoons as often people would have had a strong drink by then, except on fast days. This is also why many, many synagogues do Birkat Kohanim on Simchat Torah early on in the prayers, before the liquor starts flowing.)
Nusach Ashkenaz does connect Sim Shalom with Birkas Cohanim, as opposed to Nusach Sefard where Shalom Rav is said at Maariv due (I think) to the less obligatory nature of the prayer. The Arizal rules that Sim Shalom is to be said at all three prayers as all three are obligatory, and Sefardim and many Chasidim follow his ruling. I know the Artscroll siddurs give over reasons for all of this, but I don't have access to those right now.
According to the original Minhag Ashkenaz, Sim Sholom is recited at Mincha of Shabbos, as well as Mincha of Ta'anis Tzibbur. This is because Sim Sholom includes the phrase "Toras Chayyim" and Kriyas HaTorah is done at Minchah no those days.
As a side point, Sim Sholom and Sholom Rov were instituted for Shacharis and Ma'ariv respectively as a compromise between Bavel and Eretz Yisrael.