Rabbi David ben Rabbi Shlomo Ibn (Abi) Zimra, one of the greatest Rabbis of his time, and famed authority on Halachah, was born in Spain in the year 1479 or 1480. He was about thirteen years old when the Jews of Spain were cruelly expelled from Spain (in 1492), and he was among those who had to wander out in search of a haven. His family went to the Holy Land, and for some time he lived in Safed (Tzefas) and Jerusalem. Here, while still quite young, he became known as an outstanding Torah scholar. About the age of 31 or 32, he left Jerusalem, for some unknown reason, and came to Fez, Morocco. He became a member of the Rabbinic court under the Nagid Yitzchak HaKohen Sholal. Later he went to Egypt, where, after a short stay in Alexanderia, he finally settled in Cairo, where he became the chief rabbi of Egypt, a post he held for forty years.

The Radbaz was a man of independent means. He was a successful merchant, with business connections in other countries, like some of the Venetian merchants of his time. He amassed a considerable fortune, which he generously distributed among the poor. His saintly qualities and extraordinary scholarship endeared him to all. He had a tremendous influence not only among his people, but also in the higher spheres of the Egyptian government. His dedicated leadership brought about a great spiritual revival in the life of the Jewish communities of Cairo and Alexandria, and he instituted important by-laws to improve the standards of communal services in the synagogues, and to strengthen all aspects of the religious life of Egyptian Jewry.

One of the changes that the Radbaz reintroduced in the synagogue was to have the Reader repeat aloud the Amidah after its silent recitation by the congregation, in accordance with the long-hallowed tradition. He had found that Egyptian Jews had been following a custom according to which the congregation did not say the Amidah silently for themselves, then listened to the repitition of it by the Reader, but said the Amidah aloud jointly with the Reader, or followed the Reader's recitation of it aloud for the entire congregation. In consequence, many congregants, who did not join the Reader or listen to him attentively, failed to recite the Amidah altogether. He therefore reinstituted the age-old custom for each and all of the congregants, (including the Reader), to first say the Amidah silently, and then have the Reader repeat it aloud - the way it had been done before, and as we still do it today.

Another important institution of his was to replace the old Jewish Civil Calendar that had been in use among Egyptian and Babylonian Jews since the time of the Second Beis Hamikdosh. It became customary àt that time to date documents and contracts from the reign of Alexander óf Macedonia and the Syrian kings that followed him, as it had been previously the custom to reckon the years from the beginning of the reign of Jewish kings. The Radbaz reintroduced the custom of reckoning the years from the Creation, as had already been widely in use among Jews in most other countries, and as it is used by all today.

Rabbi David Ibn Zimra supported a large Yeshiva in Cairo, and his fame attracted many outstanding students to his Yeshiva, among them such renowned luminaries as Rabbi Betzalel Ashkenazi and the Ari Hakodosh (Rabbi Yitzchak Luria).

The Radbaz has a prominent place among the great Poskim of all times. Being recognized as a leading authority on Halachah, Rabbis and communities from far and near turned to him with questions and problems. Thus, he wrote more than 3000 responsa (Halachic decisions), most of which had been eventually gathered and published. These Shaalos uTeshuvos are of inestimable value not only from the Halachic viewpoint, but also are of great historic importance, throwing much light on various aspects of Jewish life in various communities and countries in those days. They are written in a fine and lucid style, and reflect his extraordinary learning and wisdom.

He is also the author of many other works, such as Kelalei Hagemara (Principles of the Gemara), an introduction to the Talmud, Divrei David (Words of David), notes on the Rambam's Code, Yekar Tifereth (The Honor of Glory), notes on the RaBaD in defense of the Rambam, and also a number of works on the Kabbalah, such as Or Kadmon (Original Light), Metzudath David (Fortress of David), and others.

At the age of ninety, the Radbaz leaves his post in Cairo and moves to Jerusalem. The Jewish community in Jerusalem at that time lived in difficult economic conditions, made more difficult by heavy taxation. The Arab governor of the city was an avaricious man and he imposed particularly heavy taxes on the Radbaz, coveting the substantial wealth that he had brought with him from Egypt. It was impossible for the venerable sage to remain in Jerusalem, and he moved to Safed; which was at that time a center of great Talmudic scholars and Kabbalists, among them the famed Rabbi Joseph Caro, author of the Beth Joseph and the Shulchan Aruch. The Radbaz was received in Safed with much honor and affection, and he continued his learning and writings in peaceful and happy surroundings.

Here, in the Holy Land, the Radbaz spent his last twenty years of his long and fruitful life. He passed away peacefully in the year 1589, at the extraordinary age of 110 years, and was laid to rest in Safed. But, of course, he lives on in his timeless works and immense influence which have enriched the eternal spiritual heritage of our people.