Rabbi David ben Zimra, known as the Radbaz (רדב”ז aka Ridbaz) was born in Spain in 1479. At the age of 13, when the Jews were expelled from Spain, his family moved to Israel and settled in the city of Safed (צפת). There, rabbi David learned with Rabbi Yosef Zaragosi, the Rabbinical leader of the Jewish community of Safed at the turn of the century. In 1517 he moved to Egypt where he was appointed as the Hakham Bashi, or Chief rabbi of Egypt, a position that he held for over forty years. He rejected to work for the community professionally because he feared that if his sustenance would depend on the community he would not be able to rule with objectivity. The Radbaz then dedicated himself to commerce and became a very successful merchant, dealing with wheat and leather in the international market. He amassed a great fortune, which allowed him to be financially independent form the community and even to found and support his own Yeshiba. Some of the students of that Yeshiba were great luminaries, like rabbi Isaac Luria (the Ari haQadosh), rabbi Betsalel Ashkenazi (שיטה מקובצת), and the Radbaz’s most prominent student and spiritual heir, Rabbi Ya’aqob Castro (מהריק”ש), one of the most famous rabbis in Egypt at the time .
Upon attaining the age of 90, the Radbaz resigned the chief rabbinate in Egypt and moved to Erets israel. He settled in Safed and became an active member of the rabbinical court of rabbi Yosef Caro. The Radbaz died in Safed in 1573. His inheritance, by his request, was distributed among the poor, making a special provision for Tora scholars.
The Radbaz wrote many books and close to 3000 rabbinical responsa (Questions and answers)
One of his most far reaching responsa was the one that deals with the origin of the Jews of Ethiopia, which he considered as descendants of the tribe of Dan, one of the lost Ten Tribes.
For many centuries the Rabbis have heard about a tribe in Ethiopia, which claimed being of Jewish ascendant. But for the rabbis this questions was always a theoretical question, and never a practical one. In the time of the Radbaz this question became a practical matter when a group of African captives was brought to the slave market in Egypt. A woman , with her two sons, claimed that she was Jewish, from the tribe of Dan.
The Radbaz writes (She-elot Utshubot haRadbaz, 4:219): “Once there was a Cushite woman from the land of Cush, otherwise known as Habbash [=Ethiopia] who was taken prisoner along with her two sons, and she was bought by one Reuben. We asked her what her status was, and she answered that she had been married and these were her sons by her husband, whose name was so-and-so, and this son was so-and-so. [She said that] the enemy came and killed all the people who had been in the synagogue, and the women … they took captive…”
For the purposes of this and another fascinating investigation [i.e., the origin of the Nile] the Radbaz studied the testimonies of Ethiopian scholars and he collected evidence from two Jews, one of them coming from Ethiopia, Rabbi Isaac al-Habbashi, and the second testimony from a local Egyptian merchant who had traveled to Ethiopia and met these “Jews” in their land.
The Radbaz analyzed this case from many different angles. For example, he found that these Jews did not keep some regular Mitsvot, like lighting candles before Shabbat. His argument was that the Jews from Ethiopia, they either came to their land before the rabbis issued the decree of hadalaqat nerot, or that they were descendants of the baytosim, Jews who rejected the oral tradition.
Finally, he says that the status of the Ethiopian Jews is similar to the Karaites Jews: they should accept to follow Jewish tradition, and should come under the law of redeeming captives, (pidyon shebuim), thus, the Falash Mura should be bought from the slave market and set free.
Four hundred years after the passing of the Radbaz, and based on the Radbaz’s responsa the Falash Mura were once again considered as Jews, and brought into the State of Israel.
The rabbi who made this ruling was no other than Rabbi obadia Yosef z”l. In February 9, 1973, Rabbi Obadia, then Chef rabbi of Israel, wrote an historical responsa in which he said that “based on the Radbaz… the Ethiopian tribes Falasha or Falash Mura, should be considered Jews… they should be saved from assimilation, rescued and brought to Israel under the laws of return [an Israel law that guarantees Israeli citizenship for every Jews], they should be reeducated to follow Jewish tradition, and participate in the rebuilding of our Holy Land, thus [fulfilling the words of the prophet :] “and the sons will return to their land”.
These are the original words of the responsa of rabbi Obadia Yosef
בהסתמך על הגאון הרדב”ז בתשובה (שאלות ותשובות דברי דוד הלכות אישות סימן ח) שאלו הפלשים בלי ספק משבט דן, ורק מפני שלא היו ביניהם חכמים מבעלי הקבלה תפסו להם פשטי המקראות, ודינם כתינוק הנשבה לבין הגוים, ודינם כישראל שאנו מצווים לפדותם ולהחיותם לכן באתי למסקנה שהפלשים הם צאצאי שבטי ישראל שהדרימו לכוש…והחלטתי כי הם יהודים שחייבים להצילם מטמיעה ומהתבוללות, ולהחיש עלייתם ארצה, ולחנכם ברוח תורתנו הקדושה, ולשתפם בבניין ארצנו הקדושה ושבו בנים לגבולם
Today, in a great part thanks to the Radbaz, more than 125,000 Ethiopian Jews live in Israel.