Esther 9:27–28

27 the Jews bound themselves, their descendants, and all who joinedn with them to a commitment that they would not fail to celebrate these two days each and every year according to the written instructions and according to the time appointed. 28 These days are remembered and celebrated by every generation, family, province, and city, so that these days of Purim will not lose their significance in Jewish lifeA and their memory will not fade from their descendants.o