Rabbi Mordechai of Halberstadt’s signature appears here on a financial agreement. This is Rabbi Mordechai of Dusseldorf, author of Ma’amar Mordechai. With an additional signature. Rabbi Mordechai of Dusseldorf was one of the greatest rabbis of Ashkenaz [Germany]. He was born in Halberstadt in 1685, and served for many decades as rabbi in several important communities in Ashkenaz: Halberstadt, Griesheim, Darmstadt, and finally in Dusseldorf, by which he was known. In his later years, he was elder adjudicator in Ashkenaz. He passed away in 1769 at 84 years of age. He left behind a composition on the laws of issur and heter. In it, he presents responsa from Torah geonim who preceded him, with his additions to their words, as well as responsa he wrote. Ma’amar Mordechai was printed posthumously, in 1790. The book contains many important approbations, among them, by Rabbi Mordechai Bennet and Rabbi Tzvi Yehoshua HaLevi Horowitz, son of Rabbi Shmelke of Nikolsburg. The author’s great aptitude in hora’ah [halachic instruction and rulings] is mentioned in both in the approbations and in the publisher’s foreword. Ma’amar Mordechai (siman 30) presents the revelation regarding ‘parashat heter triefot’ as copied from the Bonn Community Register, and proves that the permit, allegedly from the Prague sages, the author of Kli Yakar and the Shla”h, which was practiced by some for centuries, is fraudulent. He also wrote Kuntress Hasagot, against the opinion of the scribe Rabbi Zalman Hanau – the Raz”ah. [1] leaf, paper. 17×21 cm. Fine condition. The lower half of the leaf is slightly faded.