 In 1840 the oppressed Jews of Damascus appealed to Lehren for aid, as they did to many other influential Jews; and he took up their cause.Together with Aaron Prinz, Lehren sent a circular letter to many rabbis, which in the autumn of 1844 resulted in a protest, signed by seventy-eight Orthodox rabbis of Germany, Bohemia, Moravia, and Hungary, against the Rabbinical Conference of Brunswick (June 12–19, 1844; see "Univ.Isr."