Arranged in chronological order, the work covers the years 1666–76. In the main it consists of letters received by Sasportas, his answers to them, some letters which he wrote on his own initiative, and some comments on the development of the Shabbatean movement. Nearly half of it concerns the year 1666, from the first announcements of the appearance of Shabbetai Zevi as Messiah until his conversion to Islam at the end of that year. The second part is dedicated to the events following the conversion, 1667–68, and describes the "failure" of the Shabbatean movement. The third part consists of letters written in 1668–69, and is mostly directed against the renewed Shabbatean propaganda, which tried to explain the conversion of the Messiah and to introduce new norms of behavior suitable for the period of messianic fulfillment. The last four pages deal with the period from 1673 to 1676, sketching some of the main events of these years. Sasportas' bitter denunciation of the Shabbatean movement, its prophet Nathan of Gaza, and its believers (some of whom were his former friends), is based upon various ideological concepts. First was his adherence to the traditional conception of the messianic age; in great detail he pointed out the differences between what was happening at that time and the traditional ideas concerning the messianic era. He also saw the new movement as a revolution against established institutions and rabbinic norms, fearing that they might be set aside through the influence of Nathan of Gaza and other Shabbatean thinkers who laid claim to the faith of the populace without any appeal to rabbinic tradition. His hatred was also based on his not unfounded suspicion that the new movement contained antinomian elements, revealed in some utterances of Nathan, in the "strange deeds" of Shabbetai Zevi, and in the behavior of their followers. He frequently compared the new movement with Christianity and feared that the Shabbateans would follow the ancient example.
R. Jacob Emden (pen name Yavez; derived from Ya'akov Ben Zevi; 1697–1776), rabbi, halakhic authority, kabbalist, and anti-Shabbatean polemicist. Yavez was regarded as one of the outstanding scholars of his generation. Yavez's teacher was his father R. Zevi Hirsch Ashkenazi (Hakham Zevi). He inherited his father's interest in secular studies, his dissociation from the Ashkenazi method of study (pilpul) and customs, his stormy, independent, and uncompromising character, and his devotion to the campaign against the Shabbateans and their sympathizers. In addition, he possessed a fine literary talent, a critical tendency and a knowledge unusual for his age of general non-halakhic Jewish literature. He was also familiar with sciences and languages (German, Dutch, Latin). Despite his distinguished descent and his remarkable talmudic attainments, R. Emden occupied no official position, with the exception of a few years as rabbi of Emden (1728–1733). This made it possible for him to be exceptionally critical toward the society and the tradition of his time. He was more on guard about anything that he considered hillul ha-Shem (bringing the name of the Jew into disrepute) than for the good name of the rabbinate and of the community. He made extensive use of the private printing press he founded in Altona to disseminate his views. As a result, because of his views on a number of issues, both personal and communal, he became a figure of contention. His important halakhic works are: Lehem Shamayim, on the Mishnah (pt. 1, 1728; pt. 2, 1768); a letter of criticism against R. Ezekiel Katzenellenbogen, rabbi of Altona (1736); responsa, She'elat Yavez (2 pts. 1738–59), Mor u-Kezi'ah, on the Shulhan Arukh, OH, (2 pts., 1761–68). In addition, he published an important edition of the prayer book (whose parts had different names) with a valuable commentary (1745–48). This prayer book was reprinted several times. His main historical importance lies in his campaigns against the Shabbateans to which he dedicated many years. He relentlessly examined and investigated every suspicious phenomenon pertaining to the sect. He called upon the contemporary rabbis to publish excommunications and mercilessly attacked anyone suspected of supporting or showing sympathy to the Shabbateans. The Shabbateans were accustomed to introduce hints of their secret doctrine into their literary works, particularly in the field of Kabbalah. Consequently, R. Emden became an expert in uncovering such allusions and hidden meanings, and developed an extraordinarily sharp critical faculty by which he could recognize any suggestion of the Shabbatean heresy. Many books in which no one saw anything to which objection could be taken, were condemned by him as heretical. Though at times he was at fault and suspected the innocent without cause, his judgment in general was sound.
בשער: "באמשטרדם", בהבלטה. בשולי השער "אלה דברי יעב"ץ" הנז'. דף י,ב-יא,א: "תשובת מהרש"א (ר' שמואל אבוהב) שנדפסה בסוף ספרו דבר שמואל, ונראה, שהיא תשובה למחבר". דף מז-נט,א: "נאם המגיה (יעב"ץ)... ולשלמות הענין נציג גם מ"ש [מה שהביא] המחבר בס' התשובות שלו... אגרת שכתב המחבר... על אודות... שבתי רפאל ... המוזכר לרעה בחבור הלז... והיא בס' תשובותיו סמ"ח [סי' מח]... התשובות שכתב המחבר לענין דינא דנ"כ [דנשיאת-כפים] (בשבת שהונהג מחדש בזמן ש"ץ)... והם בספרו הנ"ל ([אהל יעקב, סי'] סח-עא)". כוללות גם "תשובת ישיבת כתר תורה שבעיר אמשטרדם" (בסי' ע). בסוף התשובות (דף נו-נט,א): "תשובת הרב בעל ההגהות (יעב"ץ)" בענין נשיאת-כפים. דף נט-ס: לוח התקון והשמטות ההגהות; מפתח הכתבים והאגרות בס' (קיצור) ציצת נובל (צבי); "מפתח לספר תורת הקנאות", שחיבר ר' יעקב עמדין, בענייני שבתי צבי ונדפס באלטונא תקי"ב. עיין: עמדן, יעקב ישראל בן צבי הירש אשכנזי (יעב"ץ). שנת הדפוס נקבעה על-פי המודעה בסוף העמוד האחרון: "הספר הלז עם שאר ספרי דבי רב הקנאי... נמצאים לקנות באמשטרדם אצל... ר' ליב ברמ"ז, בדנציג אצל... ר' חיים נר"ו מ"ץ שם. ואלה שמות הספרים...", והאחרון שבהם: "חרב פיפיות", שנדפס בשנת תקט"ז. ועיין: י. רפאל, כתבי רבי יעקב עמדן, ארשת, ג, תשכ"א, עמ' 274. על הוצאה זו כותב י. תשבי (ספר ציצת נובל צבי, ירושלים תשי"ד, מבוא, עמ' מב): "עמדן לא שינה הרבה. רק הוסיף את האגרת של ר' שמואל אבוהב... וצירף את התשובות... שיבושים רבים שבדפוס הראשון תוקנו על-ידיו והוסיף כמה הערות ענייניות". יש להוסיף שתשובותיו של המחבר שהוסיף ר' יעקב עמדן, נדפסו כאן בהשמטות ובתוספת הערות משלו.