ר' יצחק בן מלכי צדק

Rav Yitzchak ben Malkitzedek of Siponto (c. 4850/1090–c. 4920/1160), known by the acronym the Ribmatz, was among the first of the rishonim to write a commentary on the Mishnah. Only his commentary on Seder Zera’im has survived; pieces of his work on Taharot are quoted in his name by the baalei haTosafot, but the whole is lost. His father was an Italian talmid chacham, and Rav Yitzchak in time left his native town and settled in Salerno. He had at least two sons, Rav Yehuda and Rav Shiloh — it was Rav Yehuda whom Binyamin of Tudela met in Salerno, and through whom the traveler heard of the father he called the great rabbi. Rav Shiloh is mentioned in the Sefer HaIttur. From Italy Rav Yitzchak kept up a correspondence with Rabbeinu Tam.

His commentary spread through the kehillot of the Mediterranean and of Egypt, and his words were taken up and argued with by the chachamim of Fostat and of Posquières. The Raavad calls him ha-Rav ha-Yevani, the Greek rav, southern Italy standing in those years under Byzantine influence. Rav Shlomo Sirilio quotes him at length and at times prefers his reading of a mishnah to that of the Rambam; Ishtori HaParchi and the Chida both mention him, and the Maharam of Rothenburg brings him on mishnayot in Kelim and in Nega’im.

His way of explaining the Mishnah is short and to the point, close in manner to Rashi on the Gemara. Beside the two Talmuds he draws on the Tosefta, the Sifra on Vayikra, Sifrei Zuta on Bamidbar, the Targum, Seder Olam, the Aruch of Rav Natan of Rome, what Rav Hai Gaon wrote on Zera’im and Taharot, and the Sefer Mafteach of Rav Nissim. He opens up the words of the Mishnah not only with Aramaic but with Arabic, Greek, Latin and Italian words set down in Hebrew letters, which makes his commentary a resource for anyone tracing how the language of the Mishnah was once understood.

Two manuscripts of the commentary are known, one in the Bodleian Library in Oxford and one in the British Library, both containing the whole of Seder Zera’im. The commentary was printed in the Romm Vilna Shas of 1890, and in most editions of Berachot it appears in full; his commentary on Bikkurim, from the fourth mishnah of the second perek to the end of the masechet, is printed within the Mishnah commentary of Rav Shimshon of Shantz, who left none of his own there. An edited edition was published by Nisan Meir Zaks in 1975.