Esther 9:1, 15, 17, 19, 21

Now in the twelfth month, which is the month of Adar, on the thirteenth day of the same, when the king’s command and edict were about to be carried out, on the very day when the enemies of the Jews hoped to gain the mastery over them, the reverse occurred: the Jews gained mastery over those who hated them.

The Jews who were in Susa gathered also on the fourteenth day of the month of Adar and they killed 300 men in Susa, but they laid no hands on the plunder.

This was on the thirteenth day of the month of Adar, and on the fourteenth day they rested and made that a day of feasting and gladness.

Therefore the Jews of the villages, who live in the rural towns, hold the fourteenth day of the month of Adar as a day for gladness and feasting, as a holiday, and as a day on which they send gifts of food to one another.

obliging them to keep the fourteenth day of the month Adar and also the fifteenth day of the same, year by year