Saadia Gaon lived in Babylonia from 882-942 CE under Muslim rule. Much of what we know about his work comes from letters and materials found in the Cairo Geniza. Saadia was apparently one of the only geonim successful in proving that world Jewry viewed Babylonia's religious leader as more authoritative than Israel's. There had been tension between Babylonia and Palestine for generations with Babylonia obviously gaining ascendency because of their Talmud scholarship. uring Saadia's life, the Jewish intelligentsia of Babylonia spoke Arabic and were fairly easily accepted into the Arab culture. They found the Arab world very attractive, and Saadia had the job of keeping upper-class Jews Jewish. This was not an easy task. Think about America today. We dress, speak, and think American Western culture. We know some Jewish tradition, but not much. Our primary concentration is on American matters. Wealthy Jews in Babylonia, North Africa, and Spain in the tenth century had a comparable situation. Like the Jews of Alexandria, they were attracted to the rediscovered Greek philosophers and many were considering rejecting their Jewish practices. Saadia met this cultural crisis head-on and won. The high points of Muslim culture were its beautiful use of Arabic and its fondness for the Greek philosophers. Saadia wrote a philosophic work, The Book of Beliefs and Opinions, in magnificent flowing Arabic. In it, he defended the rational underpinnings of Judaism and showed logically that every rational Jew could believe in the Torah as well as Aristotle and Plato. By applying both the accepted philosophical methodology and the language revered by the Muslim culture, Saadia succeeded in refocusing many semi-assimilated Jews back on Torah and Halachah. However, it was a radical change in Babylonian Jewish tradition. Previously, the gaon had limited his work to Talmud and halachic teachings. Saadia's book of philosophy caused quite a stir. aadia didn't stop there. He wrote the first Hebrew grammar book which explained how the holy language worked. He provided a Hebrew dictionary plus a compendium of rhyming words for Hebrew poets. He was the first to write an Arabic translation of the Bible. He included commentaries, explanations, and grammatical notes as well. His translation continues to be the authoritative Bible for Jews in Arab lands. Saadia thus brought a new rich understanding of Jewish tradition to the Babylonian academies and the Jews living in the Muslim world. His philosophical work paved the way for future Jewish thinkers, and his approach to Torah influenced a century of Jews. His most important accomplishment, however, was his confrontation with the Karaities. He issued articles, letters, and responsa attacking the doctrine of the Karaites, and even declared that they were not Jews. One of his primary targets was Aaron ben Asher. The fury of his attack must have shocked the Karaites. They responded with their own letters and attacks, but their Arabic wasn't as good as Saadia's, and their defenses were less convincing. Saadia successfully defended rabbinic authority against the Karaite philosophical invasion.

R. Solomon Aaron Wertheimer, (1866–1935) was a rabbinical scholar and bibliophile. Wertheimer, born near Pressburg (Bratislava), Slovakia, grew up in Jerusalem. He became interested in the many rare books he found in Sephardi yeshivot and, despite penury, began to collect Hebrew books and manuscripts, particularly Oriental ones, including some unique specimens. Wertheimer was one of the first to publish some of the Cairo Genizah treasures. His Midrash collections, containing some hitherto unknown works, are Battei Midrashot (4 parts, 1893–97), Leket Midrashim (1903), and Ozar Midrashim (2 parts, 1913–14). A revised and enlarged two-volume edition of these collections appeared during 1948–53, edited by his grandson A.J. Wertheimer. Wertheimer also published geonic and medieval responsa: Kohelet Shelomo (1899), Ginzei Yerushalayim (3 parts, 1892–97), Zikkaron la-Rishonim (1909), and Ge'on la-Ge'onim (1925). Among his original works are Darkah shel Torah (1891), on the methodology of halakhah and aggadah; She'elot Shelomo (2 parts, 1932–33), responsa; Be'ur Shemot Nirdafim sheba-Tanakh (1924; 19532), a work on biblical synonyms. The revised edition of the last by his sons includes a biography and a bibliography of his published books and numerous manuscripts, among them commentaries on Bible and Mishnah, a siddur, a Passover Haggadah, and a supercommentary on Nahmanides' Bible commentary. Wertheimer also contributed to learned periodicals and was active as a preacher.

המקור הערבי, באותיות עבריות, עם תרגום עברי וביאורים. מעבר לשער: "אני הייתי הראשון אשר הודעתי טיב הגניזה הישנה הזאת בעולם ... והראשון אשר הדפסתי מתוך כת"י של הגניזה ההיא". עם ההסכמות מן ההוצאה הראשונה, ירושלם תרס"ח. "מפתחות המלות" נשמט.