Hi Rabbi, I was just looking up who the author was for the beautiful prayer "Nishmat Kol Chai". It seems Nishmat is a very ancient prayer from antiquity and there are several opinions as to the authorship. I was very surprised to read that Rabbeinu Tam held it was written by Simon Peter (i.e. Saint Peter from Christianity). How could it be that Peter possibly wrote Nishmat Kol Chai? Presumably, he was following early Christianity, so how could he write this poem that is part of our liturgy? Was he a faithful Jew or did he become an apostate to Christianity? The fact that this assertion seems so strange has convinced me that Rabbeinu Tam was correct on this point, otherwise, it would be very strange for him to hold such an opinion if it was baseless (of course Rabbeinu Tam is an ancient reliable source, so his opinion must be respected). I would be very interested to hear your opinion if you are aware of the history behind this. Many Thanks
The legend of Shimon ben Kafa (Peter) as the author, is just one of many possibilities raised by the "Seder Avodat Yisrael", and is based upon the appearance of the backward acronym "Shimon": Shochen, Mi yidmeh, ad hena, v'ilu feenu, and Nishmat. Rashi mentions this rumor in Machzor Vitry (p. 282), and totally dismisses it, adding that anyone who says this, must bring a large sin-sacrifice when he will go to the Beit HaMikdash. Others say the author is the tanna, Shimon ben Shetach. The Shadal cites Rabbenu Tam that Shimon ben Kafa authored a famous piyut for Yom Kippur but not (!) Nishmat Kol Chai. Also, remember that Rabbenu Tam is Rashi's grandson, so that possibility is questionable for another reason. There is a legend, not found in the classic midrashim but from outside manuscripts, that claims that Shimon (ben) Kafa (Peter) purposely "infiltrated" the rows of the early Christians, and suggested that they refrain from doing the mitzvot, as if it were, in order to attract other gentiles to the new religion. But his real motive, was to construct an insurmountable wedge between the Jews and Christians, so that Jews will precisely stay away from the new religion, as too reformative. This legend is also questionable, for supposedly it was Saul (Paul) who did away with the mitzvot, as opposed to Peter who disagreed and was opposed! In any event, R. Yehuda HaHassid, Sefer Hasidim (191), cites that Shimon Kifa was righteous but others followed him wrongly, so there may be some truth to that tradition, but still, no connection with the Nishmat prayer. In any event, Nishmat is a central prayer, accepted by ashkenzim, sfaradim and Yemenites, it's attribution to Peter is very weak, and in any event, its authorship and history is trivial and irrelevant, once it was accepted.