Machzor Vitry contains decisions and rules concerning religious practise, besides responsa by Rashi and other authorities, both contemporary and earlier. The work is cited as early as the 12th century in R. Jacob Tam's Sefer ha-Yashar as having been compiled by Simchah; and the sources from which the compiler took his material—the Seder Rav Amram, the Halakot Gedolot, and others—also are mentioned. R. Isaac the Elder, a grandson of Simchah, also refers to Machzor Vitry compiled by his grandfather. Various additions were afterward made to this machzor, a large proportion of which, designated by the letter , are by R. Isaac ben Dorbolo. The latter often appends his name to such additions; and in one place he says plainly: "These explanations were added by me, Isaac b. Dorbolo; but the following is from the Machzor of R. Simchah of Vitry himself". Other additions are by Abraham ben Nathan Yarhi, author of Ha-Manhig, and are designated by the letters, his initials.
Extant manuscripts of the Machzor
Several manuscripts of Machzor Vitry are extant, the oldest of which, according to Abraham Berliner is from Isaac Samuel Reggio, currently in the Jewish Theological Seminary of America library. It contains Machzor Vitry proper without any additions. A second manuscript, in the Bodleian Library, Oxford, is said to have marginal annotations by Eleazar ben Judah, author of the Sefer ha-Rokeach. The third manuscript is in the British Museum, and contains still other additions; this manuscript served as basis for S. Hurwitz's edition of Machzor Vitry published by the Meḳiẓe Nirdamim Society. The edition is very faulty, as the editor used no critical judgment in his work; instead of the original treatises it contains some from the Sefer ha-Terumah of Baruch ben Isaac and from the Eshkol of Ravad. A fourth manuscript is in Parma - Biblioteca PalatinaParm. 2574, which appears to be of similar age to the Reggio manuscript. A recently published paper suggests that another manuscript is earlier.
Additions to the Machzor proper
Machzor Vitry contains many prayers and liturgical poems, which are distributed throughout the work. Besides these scattered poems the British Museum manuscript has a collection of piyyutim which was published by Brody under the title Kontres haPiyyutim.. In the published edition of this Machzor there is also a commentary on the Pesach Haggadah, which, however, does not agree with that by R. Simchah b. Samuel of Vitry printed at Vilna in 1886. The latter commentary, which agrees with the one cited by Abudraham as being found in Machzor Vitry, was taken from a manuscript of that machzor—probably from the parchment copy owned by the Vilna Gaon, although no particular manuscript is mentioned in the Vilna edition itself. The published edition of Machzor Vitry also contains a commentary on Pirkei Avot. This commentary is found in the British Museum manuscript, but in neither of the others. It is really a commentary by Jacob ben Samson, the pupil of Rashi, amplified in the present Machzor. Many midrashic sayings, which are cited as such in Machzor Vitry, have been preserved in that work alone. Thus the passage cited from the Midrash Tehillim is no longer found in the present midrash of that name. Likewise there are found in Machzor Vitry citations from the Jerusalem Talmud which are lacking in the existing editions of the latter.
Editions
Machzor Vitry was published in 1891 by Mekitze Nirdamim. A new edition, based on manuscripts not previously available, was published by Aryeh Goldschmidt between 2003-2009.
