The title page, typical of the Bomberg press, brief and without ornamentation, informs that it is entitled Binyamin Ze'ev, was written by Benjamin ben Mattathias, and that work began on Thursday, 11 Tishrei 299 (September 15, 1538). It was completed, according to the colophon, on Thursday, 25 Adar I 299 (February 23, 1539). On the verso of the title page is a preface in which two reasons are given for naming the book Binyamin Ze'ev, that is, it includes the author's name, and that as the wolf "tears the prey" (Ezekiel 22:25) from all that he finds so too did he take (tear) from all that he found. This is followed by verse with an acrostic of the name Binyamin Ze'ev. Next is an index of the responsa (2a-13a) and then the author's introduction (13b-16b), where another reason is given for entitling the book Binyamin Ze'ev, namely, its value (172) is equal to עקב, which in turn equals the number of letters in the ten commandments, which includes all the taryag (613) mitzvot. There are acrostics with the names of the author and the book. The responsa fol­low (17a-573a), verse (573a) from Mattathias, R. Benjamin's son, and last a eulogy (574b-575b) from R. Benjamin for Mattathias, who had predeceased him. The text is in a single column in rabbinic type excepting headings and initial words, which are in square type.

The responsa are varied, encompassing a wide variety of subject matter. Two subjects, however, receive particular emphasis, that is, questions dealing with business matters-the responsa provide considerable information as to the economic transactions of Greek Jewry­ and with agunah. Many of his decision were criticized by Polish and Italian rabbis, among them R. Meir Katzenellenbogen (Maharam) and R. Solomon Luria (Maharshal), the former questioning R. Benjamin's reliability, the latter accusing him of plagiarism, superfluous hair­splitting, permitting usury and permitting a woman, the wife of Moses Suse, to remarry on the testimony of a single gentile witness. This last issue engendered a dispute that em­broiled many contemporary rabbis, including R. David ben Hayyim of Corfu (Maharadakh), R. Benjamin's most vociferous opponent. Among those who supported R. Benjamin are R. Bendit Axelrad and R. Joseph Taitazak.

These disputes notwithstanding, Binyamin Ze'ev is an important collection of responsa. Among those who speak highly of it is R. Moses Isserles (Rema).

בשער: והיה התחלתו יום ה יא תשרי שנת רצ"ט לפ"ק. ההדפסה נשלמה ביום כה אדר א רצ"ט. שאלות ותשובות. דף תקעג ואילך: שיר מאת מתתיהו, בן המחבר, פותח: מדותיו הטובות וברית כרותה הודיע (אוצר השירה והפיוט,ג, עמ' 80 מס' 245) והספד מאת המחבר על בנו מתתיהו; דברי יעקב בן מתתיה פואה בשבת המסייעים להדפסת הספר. על הספר והפולמוס שעורר עיין: ש' אסף, הורדת הרב ר' בנימין ב"ר מתתיה מכסא הרבנות, קרית ספר, טו, תרצ"ח, עמ' 113 ואילך; מ' בניהו, מבוא לספר בנימין זאב, ירושלים תשמ"ט, עמ' קנט ואילך. לאחר הדפסת הספר הוסמטו הסימנים רנה-רנו, "מפני דרכי שלום", ובמקומם נדפסו שני דפים ובהם טקסט חדש. כמו כן ברוב הטפסים נשמדו דפים רבים מחמת הצנזורה. השער, המפתחות וההקדמה (ועוד) נדפסו פעמיים, בשינויים. עיין: י' יודלוב, גנזי ישראל, ירושלים תשמ"ה, מס' 702; בניהו, שם, עמ' קסב-קסג.