Rava says that the proof that a makdish can't make a temurah but rather a only a mechaper can is that if we didn't hold that way then in the cse of a shaliach there would be a scenario of a tzibur that made a korban. But this is difficult because the gemarah is assuming that the makdish, meaning the shaliach, would try to make a temurah with an animal that he donated for the tzibbur. Then this is not the case of a TZIBBUR making a temurah its still a yachid. The rule of th emishnah on 13a is that a TZIBBUR can't make a temurah. (This is not a question about shalichus, I say the maharit brought down, and I saw that Rav ELyashiv, shlita, says that its not REAL shalichus. I'm asking a more simplistic question. The gemorah wanted a case of tzibbur making a temurah but this certainly seems to be a yachid making a temurah with the korban of a tzibbur.)
Mordechai Soskil, Baltimore, MD USA
The Griz (Rav of Brisk) asks your question (Shi'urei ha'Griz on Temurah). He explains that the concept of Ein Temurah b'Tzibur means that there cannot be a Temurah on a Korban that belongs to the Tzibur. Since the Makdish was Makdish the Korban for the Tzibur, it is considered a Korban of the Tzibur, and if the Makdish were to make a Temurah with it, this would constitute a Temurah b'Tzibur. We cannot say that we learn from the Din of Ein Temurah b'Tzibur that the Temurah does not take effect in this case if Makdish Oseh Temurah, because as far as the Makdish is concerned this Korban is no different than any other. However, if we say that Miscaper Oseh Temurah, since the Miscaprim are many, it makes sense to say that we learn from the Pasuk that Ein Temurah b'Tzibur.
Alternatively, he suggests that since the Mishnah says (15a) that, we do not find an instance of a Temurah that is a Korban Tzibur. If so, even if the one who made the Temurah were a Yachid, it would still be a contradiction to the rule of that Mishnah.
Dov Freedman