Pair of letters on one sheet of paper from the geonim Rabbi Moshe Katz, Av Beit Din of Nitra, and his son and successor – Rabbi Avraham Aharon, to his disciple Rabbi Avraham Yitzchak Klein, Av Beit Din of Nuremberg. Nitra, 1900. The content of the letters indicates that Rabbi Avraham Yitzchak Klein, while still residing in his father-in-law’s home, in the midst of a course training for the rabbinate, turned to his rabbis with a request for a permit to render halachic rulings [תעודת הוראה]. He also turned to his friend, Rabbi Avraham Aharon Katz, requesting that he ask his great father for the certificate in German. In his response, R’ Avraham Aharon evades this request: “Father did not attempt this – because it is not done here, as you know. And if despite this you still want it, please send me the text, and I will do my best.” The father, Rabbi Moshe, apparently came across the letter, and added a lengthy letter of his own with his signature on its reverse, and with his stamp at the top of the letter. He makes it clear in his letter that he does not grant such certificates. However, he sings R’ Klein’s praises and prays that he be successful in obtaining an important position, as befits his lofty personality: “I pray that in the merit of the Torah, you succeed in your path, and be privileged to learn and to teach with satisfaction, to bring merit to many, and find favor and good in the eyes of G-d and man. May your listeners drink your beloved and pleasant words with thirst, and may you be like an overflowing wellspring.” With enthusiastic greetings to his father-in-law in the margins. Rabbi Moshe Katz [1842-1927], son of the gaon Rabbi Menachem Katz, Av Beit Din of Tselem – was one of the Chatam Sofer’s greatest disciples. He studied Torah with his father and under Rabbi Shimon Sofer in Mattersdorf. He married the daughter of Rabbi Avraham Aharon Pasherhoffer, Av Beit Din of Frauenkirchen (of the “seven communities”); he was also a disciple of the Chatam Sofer. He started out as a maggid in Wien (Vienna), after which he was appointed rabbi of Magendorf, and Av Beit Din of Takia starting in 1891. He subsequently served as rabbi of the large city of Nitra, beginning in 1895, where he continued until his passing. Rabbi Avraham Aharon Katz [1869-1930] was a son of the gaon Rabbi Moshe Katz. He was his father’s disciple as well as that of Rabbi Moshe Tzvi Fuchs, Av Beit Din of Grosswardein. He was Ra”avad of Nitra beginning in 1901, after which he succeeded his father after the latter’s passing. Rabbi Avraham Yitzchak Klein [d. 1961], a native of Paks (Hungary), was a disciple of the gaon Rabbi Moshe Katz, and then of the author of Shevet Sofer in the Pressburg yeshivah, where he befriended his son, Rabbi Akiva Sofer (author of Da’at Sofer), who eventually became the rosh yeshivah – a friendship which continued their whole lives. He was the son-in-law of Rabbi Elazar Mintz, rabbi of Kempen (near Poznań). He began studying for the rabbinate after his marriage, and he also studied philosophy at the University of Breslau in order to earn an academic degree. He was appointed as rabbi of Adath Israel of Nuremberg in 1909, serving there until Kristallnacht. He ascended to the Land of Israel in 1939, where he was offered the position of rabbi of the Mekor Chaim community in Haifa. He led that community until his passing. His son-in-law was the educator R’ Yosef Avraham Wolf. Sheet of paper divided into to parts, 22×14 cm each. Fine condition. Aging stains.