Esther 9:18-21

18But the Jews that were in Shushan had assembled on the thirteenth and on the fourteenth and on the fifteenth they rested, making it a day of feasting and gladness.

19That is why the rural Jews—those living in unwalled villages—make the fourteenth day of the month Adar a day of gladness and feasting, a day of sending presents of food to one another.

20Mordecai recorded these events and he sent letters to all the Jews throughout the provinces of King Ahasuerus, both near and far,

21urging them to celebrate the fourteenth and fifteenth days of Adar every year