Ester 9:1

The Jews Prevail over Their Enemies

9:1 In the twelfth month (that is, the month of Adar), on its thirteenth day, the edict of the king and his law were to be executed. It was on this day that the enemies of the Jews had supposed that they would gain power over them. But contrary to expectations, the Jews gained power over their enemies.

Ester 9:18

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.

Ester 9:21

9:21 to have them observe the fourteenth and the fifteenth day of the month of Adar each year