The Common version of certain prayers found in the Jewish Liturgy indicate that they may have originated in the Exile. One example is in Mussaf of Shabbat (Siddur Rambam, Appendix to Sefer Ahahva, Oxford Bodleian Hunt. 80 (Catalogue Neubauer 577), fol. 176a.)
Such is also the reading in Siddur of R. Sa'adiah Gaon, (Oxford Bodleian Ms Hunt. 448; Catalogue Neubauer 1096, fol. 85a; publication- Davidson, Assaf, Yoel 1963, p.118). and Siddur Shlomo ben Nathan MiSajelmassa, (Oxford Poc. 262; Cat. 896; ed. Kroizer 1995, p. 35). It seems more logical that this is an exilic prayer tailored for its adaptation in the Erez Israeli Siddur, than to suggest that this is the original version of the prayer and "vesham" was added in the Diaspora version. The theme "sheta'alenu learzenu" indicates that the prayer as a whole is organic to the Exile. An Erez-Israelite composer is more likely to supplicate for the ingathering of his co-religionists from the exile, as found in the abovementioned T-S H5 version.
Worth mentioning; is the "sham" in the blessing after the Passover Haggadah: ונאכל שם מן הזבחים, (R. Akiva in Mishnah Pesahim X 6)) is clearly relating to Jerusalem only, yet is missing in the Eretz Israeli Mishnah (Kaufmann, seen below, and Parma): לוכל, לאוכל. This version is also recorded in the Mishnah in Alfasi's halakhot Genizah Cambridge T-S G2, 52, and goes as far as Rambam in both Commentary on Mishnah and the very reliable Sutro 117 copy of Mishne Torah (Hametz VIII 5).
|Mahzor Paris BN Heb. 646 fol. 243a|
This is apparently not only an alteration for geographic context, but justified both by content and source text. There is no commandment to abolish idolatry outside of "our land" (Sifri on Duet. XII 3) thus the blessing upon seeing a demolished site of idolatry is perscribed in Mishna Berakhot IX 1 (and Tosefta Berakhot VI ) הרואה מקום שנעקרה ממנו עבודה זרה מברך ברוך שעקר עבודה זרה מארצנו
See important comments and addtions to this article in the MenachemMendel blog- here.