Manuscript, Yesod Ha’Ibur, rules and laws regarding Ibur Hashana, by Rabbi Yosef son of Rabbi Yehudah Hachazan of Troyes. [Ashkenaz, 16th century].
Fine semi-cursive Ashkenazi handwriting, typical of the period, with initials in red ink. Includes many tables for calculation of New moon. Title page at the beginning of the manuscript which was added during a later period.
Introduction at top of manuscript: “The foundation of the Ibur [declaring a leap year] which was established by the wise Rabbi Yosef son of Rabbi Yudah Hachazan of Troyes, is calculation of the New moon of any given month, and although I have already written regarding this matter I will not refrain from writing this excellent method of calculation through which many secrets have been revealed and many mysteries have been solved and which can be attained only by this method which was handed down by my forefathers”.
Rabbi Yosef son of Rabbi Yehudah Hachazan of Troyes, among scholars of France during period of the Rishonim (approximately 13th century). Several compositions written by him are known, among them Sefer Yedidot on the wisdom of grammar (which is cited in the Minchat Yehudah commentary on the Torah, by Rabbi Yehudah son of Elazar, one of the authors of the Tosfot) and several compositions on the wisdom of leap years, one of which is the composition in this manuscript.
Apparently, this is the only copy of this composition, that has not been printed.
Notations and ownership signatures. Last page contains listing of planets and signs of zodiac.
[1], [28] leaves + 4 blank leaves. 15 cm. Good condition, stains and slight wear.