R. Judah Ben Barzillai ("Ha-Nasi"), Al-Bargeloni (late 11th and early 12th century), rabbi of Barcelona. Nahmanides claimed descent from him, referring to him as "zekeni" ("my ancestor"). According to one statement (responsa, Tashbez, 1:15), he was a pupil of R. Isaac b. Reuben of Barcelona, but this is not substantiated from any other source and is open to question. The assumption that R. Abraham b. Isaac of Narbonne was his pupil is unfounded, even though Abraham constantly refers to his teachings. He was a contemporary of R. Abraham b. Hiyya, with whom he engaged in an interesting controversy on the question of postponing a wedding date for astrological reasons. Judah was strongly opposed, since he regarded it as contrary to Jewish law. Judah's works consistmostly of codes which were highly regarded in their time, but most of them were subsequently lost. Quotations from them by other authors show that they embraced all the halakhah which applied in practice. His works are (1) Sefer ha-Ittim, dealing with Sabbath and festivals in the Jewish calendar, and of which there have been published – with many errors – only those concerning the Sabbath, with commentaries by R.J. Schorr (Cracow, 1902), and two further fragments, by J.L. Zlotnick (see bibliography); (2) Yihus She'er Basar, on marriage and personal law, known through a few quotations; (3) Sefer ha-Din, on civil law, of which the Sefer ha-Shetarot only has been published (Berlin, 1898). In 1928 S. Assaf published Likkutei Sefer ha-Din, a précis of the original book (Madda'ei ha-Yahadut, 2, 1926); (4) commentary on Sefer Yezirah (Berlin, 1885). This work is a mine of information on geonic and philosophical literature.

One important aspect of Judah's commentary on Sefer Yezirah is that in it he quotes extensively from the Ishrūn Maqālāt ("Twenty Tractates") of Al-Mukammis. Since only a small portion of this work has been published, Judah's summaries are the major source of Al-Mukammis' teachings. Among Judah's own philosophical contributions were his polemics against dualistic and trinitarian doctrines (Commentary on Sefer Yezirah, 75, 175), and especially against Christian allegorism (ibid., 77). Even when not polemicizing, he tried to interpret all of Scripture with a view to removing doubts about God's total spirituality. Among other philosophic doctrines he held that the revelations received by the prophets were emanations of the Divine Spirit, the first created being, to which Scripture also refers as the "glory of God" (ibid., 16, 119, 174). At the end of his commentary Judah reproduced a considerable portion of one early Hebrew translation (no longer extant) of about half of Saadiah's commentary on Sefer Yezirah.

The publisher and editor of this work, R. Solomon (Zalman) Hayyim Halberstam, (ShaZHaH, 1832–1900), was a Polish scholar and bibliophile. R. Halberstam was born in Cracow and studied with his father, Isaac Halberstam, an eminent talmudist. During his years as a successful merchant in Bielsko (Bielitz), Poland, he collected rare books and manuscripts. He studied some and lent others to Jewish scholars. Halberstam was one of the founders of the Mekize Nirdamim society. In addition to scholarly articles and notes to the works of other scholars, he published with introductions and notes some of the manuscripts from his library, among them being R. Yom Tov b. Abraham's novellae on tractate Niddah, Hiddushei ha-Ritba (1868); R. Abraham ibn Ezra's Sefer ha-Ibbur (1874); and R. Judah b. Barzillai's Sefer ha-Shetarot (1898) and Perush Sefer Yezirah (1885). In 1890 he published Kohelet Shelomo, a catalog of his manuscripts which listed 411 items. After R. Halberstam's death most of his manuscripts were sold to the Judith Montefiore College in Ramsgate, England, and are now at Jews' College, London. The majority of the printed books in his library and a small part of his manuscript collection were acquired by the Jewish Theological Seminary in New York and the library of the Vienna community. Most of his correspondence is preserved in the library of the Jewish Theological Seminary. Halberstam also wrote notes to H. Michael's bibliographical work Or ha-Hayyim (in the Mosad ha-Rav Kook edition, 1965).

עמ' 354-334: הערות נוספות מאת דוד קויפמאנן, בודאפעסט, יא ניסן תרמ"ו[!]. "הגהות, הוספות ותקונים לפירוש ספר יצירה", מאת שזח"ה, קויפמאן, אברהם עפשטיין, יעקב רייפמאן ואברהם מתתיהו חלפן, נתפרסמו בקבץ על יד, ב, תרמ"ו, עמ' 17-1; ג, תרמ"ז, עמ' 23-13.