The passing of Rav Yaakov ben Asher (the Tur) (1348)
Rav Yaakov ben Asher, son of Rav Asher ben Yechiel (the Rosh), was one of the most prominent Torah scholars in medieval Europe.
His classic work on Jewish law, named the Tur, also known as Arba'ah Turim ("The Four Rows," an allusion to the jewels on the High Priest's breastplate), is a 14th-century legal code. It traces Jewish law from the Torah through the Talmud and early legal authorities, citing the author's dissenting opinions. The work is divided into four sections covering all practical law areas, excluding laws only relevant in Temple times.
As the name implies, the Arba'ah Turim consists of four divisions ("Turim"), which are further organized by topic and section.
The four Turim are as follows:
Orach Chayim - laws of prayer and synagogue, Sabbath, holidays
Yoreh De'ah - miscellaneous ceremonial laws, such as shechita and kashrut
Even Ha'ezer - laws of marriage, divorce
Choshen Mishpat - laws of finance, financial responsibility, damages (personal and financial), and legal procedure
In the Arba'ah Turim, Rabbi Yaakov traces the practical Jewish law from the Torah text and the proclamations of the Talmud through the Rishonim. He used the code of Rabbi Yitzchak Alfasi (Rif) as his starting point; these views are then compared to those of Rambam and the Ashkenazi traditions in the Tosafist literature.
Unlike Rambams' Mishneh Torah, the Tur is not limited to normative positions but compares the various opinions on any disputed point. (In most instances of debate, Rabbi Jacob follows the opinion of his father, Rabbi Asher ben Jehiel, the Rosh.) The Arba'ah Turim also differs from the Mishneh Torah in that, unlike Maimonides' work, it deals only with areas of Jewish law applicable in the Jewish exile.
The best-known commentary on the Arba'ah Turim is the Beis Yosef by Rabbi Yosef Karo. This commentary goes beyond the normal functions of a commentary in that it attempts to review all the relevant authorities and reach a final decision on every point, constituting a comprehensive resource on Jewish law.
Other commentaries are Bayis Chadash by Rabbi Yoel Sirkis, Darkhei Moshe by Rav Moshe Isserles (Rema), Perishah u-Derishah by Rabbi Yehoshua Falk, as well as works by several other Acharonim.
Rav Yosef Caro's Shulchan Aruch, the fundamental work of Halakha, is a condensation of his Beis Yosef and follows the basic structure of the Arba'ah Turim, including its division into four sections and chapters - Tur's structure down to the siman is retained in the Shulchan Aruch.
The views in the other commentaries are often relevant in ascertaining or explaining the Ashkenazi version of Jewish law, as codified by Rema in his Mappah.
Students typically study the Tur and the Beis Yosef concurrently with the Shulchan Aruch itself: in some editions, the two works are printed together to allow comparison of corresponding simanim.
The "Tur" also authored a famous commentary on the Torah, uncovering layers of hidden meaning in the text through gematria (and other close analyses of the texts).