Esther 9:15

9:15 The Jews who were in Susa then assembled on the fourteenth day of the month of Adar, and they killed three hundred men in Susa. But they did not confiscate their property.

Esther 9:18-19

The Origins of the Feast of Purim

9:18 But the Jews who were in Susa assembled on the thirteenth and fourteenth days, and rested on the fifteenth, making it a day for banqueting and happiness. 9:19 This is why the Jews who are in the rural country – those who live in rural cities – set aside the fourteenth day of the month of Adar as a holiday for happiness, banqueting, holiday, and sending gifts to one another.