In 1660 in Prague, Hannover published Safah Berurah ("Clear Language"), a Hebrew-German-Latin-Italian conversation lexicon, text, and guidebook for travelers, and in 1662, Sha'arei Ziyyon ("The Gates of Zion"), a collection of prayers for tikkun hazot ("midnight prayers"), and for other kabbalistic rituals of the Lurianic school. These two books were the result of his studies in Italy. In 1662, he was appointed president of the bet din and head of the yeshivah in Jassy, Walachia, which was then a Turkish province. He was still in Jassy in 1666, the "year of redemption," when the Messiah was due according to the beliefs of the Shabbatean movement. He is mentioned among those who wrote to Lithuania to announce the event. He spent about ten years in Jassy and, according to tradition, in Pascani too. He then moved to Ungarisch Brod, Moravia, on the Hungarian border, where he was preacher and religious judge. He was killed, while praying with the community, by Turkish soldiers who raided the town. Hannover was a prolific writer, but most of his works, sermons and writings on the Kabbalah, were lost. Apart from the sermon Ta'amei Sukkah, printed in Amsterdam, 1652, and a kabbalistic writing on Purim, preserved in manuscript, only the three books published in his lifetime are extant. The subject matter and the style of these works are diverse, yet each had considerable influence for a long time. The prayer book, Sha'arei Ziyyon, was reprinted over 50 times, chiefly in Italy, Holland, and Central and Eastern Europe. The book served as a channel for introducing into the ordinary prayer book certain elements of the Lurianic Kabbalah, such as the Berikh Shemei prayer. Safah Berurah also had several editions, being published both under its own title and other titles in its original form and in a modified version. Up to the 19th century, it was used for the study of foreign languages in Central and Eastern Europe. It is still an important source for research into the Yiddish and the Hebrew used in the author's time. The small book Yeven Mezulah, on the Chmielnicki pogroms of 1648–52, has relatively few personal experiences of the author. It is mainly based on eyewitness accounts of others and hearsay evidence (including information Hannover found in print). This was the manner of writing of chroniclers of the period. Hannover's broader vision, lucid language, and simple and graceful manner of relating events gave the book an appeal it still retains. Among the Ashkenazi Jews, it was reprinted in the original version and in Yiddish translation, in almost every generation (including Hebrew edition, 1945; Yiddish edition, 1938), It was translated into French (1855), German (1863), Russian (1878), Polish (1912), and English (Abyss of Despair, 1950).

בהוצאה זו נוספו תפילות, פיוטים והנהגות, לעיתים קטעים קצרים ולעיתים חטיבות ארוכות. כך נוספה בשער ג (בדפים יז-כז) חטיבה ארוכה הכוללת "תפלות על דרך הקבלה" מהאר"י לשבעת ימי השבוע, "שבעים ושתים פסוקים עם ע"ב שמות", תפלה ליושב בבית האסורים מאת ר' יהודה אריה ממודינה ו"תפלה להתפלל על החולים". "תקון ערב ראש חודש" (בשער ו) שבהוצאה הראשונה כלל עמוד אחד בלבד הורחב מאוד (דפים כג-מז,א). בסוף הספר נוספו "קדיש וברכו" (תפילות במקום קדיש, ברכו וקדושה בציבור) "שסדר... ר' יעקל בן... ר' אברהם שעפטלש [הורוויץ]" ו"זמר נאה כשנותנין ספר תורה לבית הכנסת", "יסדו... ר' ירמיה [ב"ר יהודה] בק"ק ווערטום במדינת אשכנז", שאר-בשרו של המחבר. פותח: אשירה לה' ואזמרה. בקהל עם עזוזו להספרה (אוצר השירה והפיוט, א, עמ' 362, מס' 8012). נשלם בחצי כסליו תל"ב.

הסכמות ר' יצחק ב"ר אברהם מפוזנא, ר' נחמן ב"ר מאיר כ"ץ רפאפורט, ר' שמואל שמעלקא [ז"ק] ב"ר מאיר מאוסטרה ור' ישראל ב"ר אהרן בן ציון מסאטנב, שהועתקו מן ההוצאה הראשונה, פראג תכ"ב.