||The age of this ms. is somewhat in dispute, the Hebrew University in Jerusalem who maintains a copy of the present work dates the ms. to the 15th century, other suggests it can be dated to as late as the 19th century.
Tanhum b. Joseph ha-Yerushalmi (c. 1220–1291), philologist and biblical exegete. Few biographical details are known of him. As his name indicates, either he or his family originated from Jerusalem, and according to Bacher, he lived for some time in Erez Israel and subsequently went to Egypt, where he died. Tanhum had an extensive knowledge of philosophy, and knew a number of languages, including Arabic and Greek, and it would appear that he knew medicine (Al-Murshid al-Kafi, S.V. tavlul). He had a profound knowledge of all the biblical exegetes and grammarians who had preceded him (there are more than 250 references in the section of his Al-Murshid al-Kafi to the letter tav alone, many of which are not identifiable). He was the last representative of the rational school of biblical exegetes in the East, but the "central pillars" upon which he based his works were "the words of the revered Rabbi Moses b. Maimon in his scientific outlook and his religious beliefs, and the words of R. Jonah ibn Janah in grammar and philology."
One of his works which has survived is Kitab al-Bayan, consisting of commentaries on the books of the Bible, with an introduction (or first part) called Al-Kaliat ("General Principles"), a work which earned him the title of "the Ibn Ezra of the East." Portions of this commentary are scattered in various libraries, such as the Bodleian and the Guenzburg libraries. In addition to fragments which have been published in various learned periodicals, there have appeared his commentary on Judges, Samuel, Kings, and Jonah (T. Haarbruecker, 1842–62); Habakkuk (S. Munk, 1843); Lamentations (G. Cureton, 1843); Ecclesiastes (S. Eppenstein, 1888); and Psalms (idem, 1903). Another extant work is the above-mentioned Al-Murshid al-Kafi, a lexicon giving in alphabetical order the nouns and verbs in Maimonides' Mishneh Torah. This work is of considerable importance on account of the new Hebrew terms which he coined, and it constitutes the greatest codex of Maimonides' work. Most of the introduction, as well as a number of entries in the work, was published by W. Bacher under the title Aus dem Woerterbuche Tanchum Jeruschalmi's (1903).