[Letter of Shabbethai Tzevi, on reversing days of mourning in Judaism]late 18th cent.?]Text of a letter written by the Jewish false Messiah Shabbetai Tzevi in the summer of 1666 and copied by the Doenmeh (or Dönme) sect. According to the scholar Yaron Ben-Naʾeh, this copy was probably written around 1800. In this previously unknown letter,text