Ibn-Koreish, Jehudah one of the earliest Jewish lexicographers, flourished in the latter half of the 9th century at Tuhart or Tahort, in Africa, and was one of the first who wrote on comparative philology. He was thoroughly conversant not only with the Berber tongue, but also with the three Shemitic languages; he had carefully studied the traditions of the Jews and the Mohammedans, and was eminently qualified to write on the Hebrew language, and introduce frequent comparisons with the other Shemitic tongues. His works are, אַגָּרוֹן, a Hebrew Lexicon in alphabetical order, but with that peculiar arrangement which all works of this class were subject to at that time, viz. each group of words belonging to a letter was accompanied by introductions, one on those words which have only the letter in question for a radical theme, and another on the changes of that letter. The work has been lost, but its existence is attested by the fact that not only the author himself refers to it in another of his works, but also the great scholars of his and subsequent periods; — Risalet (Heb. רסאלה), or a letter addressed to his Jewish brethren at Fez, in which he exhorts them to continue the study of the Aramaic Targum, and of the Aramaic as well as the Shemitic languages, without a thorough knowledge of which the Old-Test. Scriptures can only be imperfectly comprehended. After the introduction he divided the work into three parts. In Part I he arranged in alphabetic order all difficult Hebrew words that could only be properly understood from the Chaldee paraphrases of Onkelos and Jonathan ben-Uziel. Pait II contained an explanation of Biblical Hebrew words found also in the Mishna and the Talmud. In Part III he instituted a comparison with the Arabic of all analogous Hebrew roots, forms of expressions, prefixes and suffixes, etc. This work is certainly a very important contribution to Hebrew philology, and it is only to be regretted that we do not possess it completely, since the first part breaks up with letter כ, and does not begin again till letter ת, from which Furst (Hebr. Dict. vol. 23) infers that the author intended it only as a continuation of his (lost) Hebrew Dictionary. It has lately been published in the Arabic under the title Epistola de studii Targum cutilitate et de linguce Chaldaicae, Misnicae, Talmudice, Arabicae, vocabulorum item nonnullorum barbaricorum convenientia cum Hebrea; ediderunt J. J. L. Barges et D. R. Goldberg (Paris, 1857). The introduction, with specimens from the work, have been published in Arabic, with a German translation by Schnurrer, in Eichhorn's Allgem. Bibliothek d. Biblisch. Literatur (Lpz. 1790), 3:951 sq.; the introduction has also been published with a German translation by Wetstein in the Literaturblatt des Orients (1845), 3:2; and extracts are given by Ewald and Dukes, Beitrage zur Geschichte d. Aeltesten Auslegeng und Spracherklairung d. A. Test. (Stuttgart, 1844), 1, 116-23; 2, 117, 118. He wrote alsסֵפֶר דַּקדּוּקo a Hebrew grammar, which Aben-Ezra used in the preparation of his own work. See, besides the works already referred to, Gratz, Gesch. d. Juden, 5, 293; Kitto, Cyclop. Biblical Lit. 2, 357; First, Biblioth. Jud. 2, 203.