Rabbi Yitzchak was born in 1013 in the City of Kal’a in Algeria. He learned Torah in the Yeshiva of Kairuwan under the tutelage of Rabbi Chananel ben Chushiel Gaon. But he was forced by fanatical Muslims to flee with his family to Fez in Morocco, where he remained for forty years as head of the community and its Yeshiva, and it was there that he completed his greatest work, the Sefer HaHalachot, (see below). It was there also that the name of the city became intertwined with the name of the great Torah scholar, for “Rif” stands for Rabbi Yitzchak of Fez, or Rabbi Yitzchak al-Fasi.
As a relatively young man, Rabbi Yitzchak had become aware that most people were unable to deduce the halacha, the actual Jewish Law, from the text of the Talmud. He conceived the idea of a “commentary” that was essentially an abridgement of the Talmud, containing only the material that was pertinent to the determination of the final halachic conclusion. Omitted were all Aggadic, or legendary material and even the “shakla v’tarya,” the back-and-forth running dialogue, that scholars see as the “soul” of the Torah she-B’Al-Peh, the Oral Torah, were omitted for the sake of halachic clarity. The body of this commentary, that encompassed Moed, Nashim, Nezikin, Brachot and Chulin, was called the “Sefer HaHalachot,” the Book of Jewish Laws.
In Fez, there was an extremely wealthy man who, because of his wealth, assumed a position of great distinction in the community. Unfortunately for that individual, Rabbi Yitzchak knew that he had amassed his wealth by corrupt means and therefore refused to show him deference. That person informed falsely against the Rif to the government, forcing the great Torah scholar again to flee, this time from North Africa to Spain.
He was received with great honor by the Jewish Community of Cordova. The following year, he assumed the position of Head of the Community and Head of the Yeshiva of Lucena, when those positions became vacant with the death of Rabbi Yitzchak ibn Gias. It was there that the “best and the brightest” of his students was Rabbi Yoseph ibn Migash, about whom the Rambam writes that when he thinks of how much Torah the Ri Migash knew (actually, it was Rabbi Maimon, father of the Rambam, who was the student of the Ri Migash, but he passed along the Torah of his great teacher to his son), his head aches. Thus the Rif succeeded in transmitting the Torah traditions of the Geonim and the Babylonian Yeshivot to the Rambam and his generation.
When several leaders of the Community of Lucena expressed reservations about his appointment due to his advanced age, Rabbi Yitzchak of Fez assured them that he would celebrate his “Bar Mitzvah” in Lucena. And he was true to his word, passing away there in 1103, after thirteen years of creative and productive service.
Sources: Orthodox Union