In consequence of the law of June 10, 1813, which made the "Schutzjuden" citizens of Bavaria, and which demanded that the rabbi should have a university training, Rosenfeld submitted to a new examination. In 1826 he was elected rabbi of Bamberg, which post he held until his death. He took an active part in the work for the emancipation of the Bavarian Jews, and wrote a number of pamphlets on this subject (see Jew. Encyc. ii. 604b).
Rosenfeld edited "Stunden der Andacht für Israeliten" (4 vols., Dinkelsbühl, 1834; 2d ed., 3 vols., ib. 1838). Selections therefrom in Hebrew by M. Bendelsohn of Grodno appeared at Wilna in 1854 under the title "Hegyon ha-'Ittim." In 1835 and 1836 Rosenfeld published the weekly "Das Füllhorn."