Esther 9:30-31

30And Mordecai sent letters to all the Jews in the 127 provinces of Xerxes’ kingdom—words of goodwill and assurance—

31to establish these days of Purim at their designated times, as Mordecai the Jew and Queen Esther had decreed for them, and as they had established for themselves and their descendants in regard to their times of fasting and lamentation.