Sefer Agur, laws and customs, by R. Yaakov Baruch Ashkenazi Landau. [Naples: Azriel Gunzenhauser, ca. 1490]. First edition. Incunable.
First edition of Sefer Agur, an important halachic work by R. Yaakov Baruch Ashkenazi Landau, a Torah scholar of Germany and Italy in the second half of the 15th century. The book is a compilation of many laws and customs from the Rishonim, in particular the customs of Germany and France. The book includes laws of prayer, tzitzit, tefillin, blessings, Shabbat and festivals, shechitah and bedikah, kashrut, Niddah and mikvaot.
The author, who composed his book as if lecturing to his disciple, was concerned that Torah would be forgotten, due to the many doubts, conflicting opinions, and new oral teachings (as stated in the foreword), and he therefore made sure, in each topic, to quote both the doubts raised by earlier poskim, and the customs and practices he was taught by his teachers. Sefer Agur had a great impact on halachic literature, and many subsequent poskim, including the Beit Yosef, Rema, Maharshal and those of the next generation – the Bach, Magen Avraham, Taz and Shach, relied heavily on his rulings.
Printed together with Sefer Agur was R. Yaakov Landau's second book, Sefer Chazon (lacking in the present copy) – halachic riddles and their solutions (the riddles were only printed in full in the first two editions; in subsequent editions, they were either omitted entirely or only printed partially). For more information about R. Yaakov Landau and his works, see: R. Moshe Hirschler, Biography of R. Yaakov Landau and Sefer Agur, Introduction to Sefer HaAgur HaShalem, Jerusalem, 1960, pp. 6-14.
The author was presumably involved in the printing of his book. After he left Germany for Italy (the year and reason for his move are unclear), R. Yaakov Landau reached Pavia in ca. 1480 (where he composed Sefer Chazon), and later Naples, an important Torah center in those days. In Naples, he worked as proofreader in the printing firm of Joseph Gunzenhauser, and presumably even proofread his own book (at the end of the book of Tehillim with the commentary of the Radak, printed by Gunzenhauser in 1487, there is a colophon signed by the proofreader, R. Yaakov Landau. The colophon contains an interesting description of the rigors of the proofreading work in those times).
Printed in square type. No imprint date (see below).
Sefer Agur is the second Hebrew book printed in the author's lifetime (preceded by Nofet Tzufim by R. Yehuda Messer Leon, who granted an approbation to the present work).
Likewise, this is the first book to contain approbations (appeared originally at the end of the book; lacking in the present copy). See: Aryeh Tauber, Mechkarim Bibliografiim, Jerusalem, 1932, p. 16, note 1.
Handwritten marginal inscription in square script on one leaf: "I acquired this Sefer HaAgur in 1795, Yosef son of Ezra the scribe". Additional inscription by the same writer on a different leaf. Appropriate headings were added in handwriting to some leaves.

Incomplete copy. [153] leaves. Originally: [186] leaves. Lacking: 33 leaves (including final leaf of gatherings xxiii and xxiv – originally blank leaves). Collation: i7 (lacking first leaf with engraved border), ii-ix8, x4 (lacking leaves 3-6), xi-xiii8, xiv4, xv-xviii8, xix7 (lacking final leaf), xxii8 (lacking gatherings xx4 and xxi8), xxiii3 (lacking final blank leaf and gatherings xxiv8 and xxv6). Missing leaves replaced in photocopy. Approx. 19 cm. Condition varies. Most leaves in good-fair condition, some leaves in fair condition. Stains, including dark dampstains. Marginal open tears to many leaves, not affecting text, repaired in part with paper. Large open tears and worming to several leaves, affecting text, repaired with paper. Some leaves presumably provided from a different copy. New leather binding, placed in matching leather slipcase.

The printer Joseph Gunzenhauser established his printing press in Naples, ca. 1487, where he and his son Azriel printed some 13 books. See: Y. Yudlov, A Document Regarding the Sale of Incunabula in Naples in the Fifteenth Century, Asufot, X, 1997, pp. 74-87.
Regarding the date of printing, see: A. Tauber, Sefer HaAgur, Kiryat Sefer, VI, 1929-1930, pp. 525-526; ibid., VII, 1930-1931, p. 171 (he maintains that the book was printed ca. 1500); A.M. Habermann, ibid., p. 166; I. Sonne, ibid., p. 169.
Regarding the variations between different copies, see: Yitzchak Rivkind, Dikdukei Sefarim, Kiryat Sefer, X, 1933-1934, p. 491, no. 2; A.K. Offenberg, Hebrew Incunabula in Public Collections, Nieuwkoop: De Graaf, 1990, no. 82.