Dr. Spiegel was born in 1899 in the town of
Bukovina, Romania to parents Regina and Simon Spiegel, a tobacco wholesaler. His brother was the film producer
Sam Spiegel. He studied at
Israelitisch-Theologische Lehranstalt (Israelite Theological College) in Vienna and in 1922 received his doctorate from the University of Vienna. For several years he was a youth leader in Ha-Shomer ha-Ẓa'ir, a Zionist youth movement which prepared Jewish youth to live in collectives in Israel. He also taught in various schools in Israel from 1923–29. From 1929 to 1943, Spiegel taught Biblical and Post-Biblical Literature at the
Jewish Institute of Religion in New York City, while also holding the position of librarian. After the death of
Israel Davidson he joined the
Jewish Theological Seminary of America as professor of medieval Hebrew literature in 1944. His research concentrated on biblical and medieval Jewish literature, especially the prophets Hosea, Amos, Jeremiah, Ezekiel, and Job. He extensively researched liturgical poetry (
piyyut in Hebrew) and devoted more than fifty years of research creating a definitive edition of the liturgical compositions of
Eleazar Kallir. as well as the religious poetry of Kallir's predecessors and contemporaries. He collected material until his death, but never published it.
In 1996 Menahem Schmelzer published a volume entitled
Avot hapiyyut (The fathers of the piyyut) from the materials found in Spiegel's literary estate. He was famous for his erudition and thoroughness as well as his beautiful writing style in Hebrew and in English. Largely due to Truman’s urging, the talk was published the following year as a small pamphlet entitled Amos versus Amaziah. Spiegel served as chairman of the educational advisory committee to Hadassah, as secretary of the
Alexander Kohut Memorial Foundation, and as a trustee of the
Israel Matz Foundation. He was active in the
Mekize Nirdamim Society, founded in 1862. Spiegel was an avid writer and corresponded with the leading scholars and Jewish intellectuals of the day as well as with many of his former students and colleagues in Israel and New York City. Spiegel was also an acclaimed speaker and schools, synagogues, and congregations across the United States invited him to lecture at their institutions. Some correspondents of note include
Alexander Marx,
Gershon Scholem,
Ben Zion Bokser,
Moshe Davis,
Louis Finkelstein,
Louis Ginzberg,
S.D. Goitein, Judah Goldin,
Abraham Joshua Heshel,
Saul Lieberman,
Stephen S. Wise,
Henrietta Szold,
Israel Davidson,
Mordecai M. Kaplan, E. E. Urbach, and Menahem Zulay. == Awards and memberships ==