Feder was born into a poor Jewish family in Václavice (Benešov district). He studied at the German-Jewish school in Benešov, graduated from the Piarist grammar school in Prague and then studied at the Rabbinical seminary and Faculty of Philosophy in Vienna. After graduating, he became a rabbi, serving in Kojetín, Louny and Roudnice. He then served as a rabbi in Kolín for over thirty years, also teaching at the school of commerce there and being generally very active in the cultural sphere.
Feder was the author of a number of religious tracts and textbooks, from which generations of Czech Jews studied. He was a member of the Czech-Jewish movement, and contributed to the Czech-Jewish calendar.
After the occupation of the Czech lands by the Nazis and the creation of the Protectorate, Feder realised what danger threatened Czech Jews, and tried to ensure the mass evacuation of his Jewish community in Kolín to anywhere where they might be out of the reach of Nazi power. However, none of his emigration projects, the most hopeful of which was to French Guinea, could be implemented.
In 1942, together with other Jews from Kolín, he was deported to the Terezín ghetto, where he acted as rabbi for the whole of the ghetto's existence, being described by his fellow prisoners as a great moral support. He survived in Terezín until the liberation, but his wife and most of his family died during their imprisonment.
After liberation, Feder first returned to Kolín, where he helped to reestablish the Jewish religious community. He then served as the chief land rabbi in Brno. Feder was very active in attempts to commemorate Czech victims of the Nazis' final solution to the Jewish question. In 1947 he dedicated a book, Židovská tragédie (The Jewish Tragedy), to his murdered fellow citizens from Kolín, and he founded the tradition of annual commemorative meetings at Terezín.
