Esther 9:22-27
English Standard Version
23So the Jews accepted what they had started to do, and what Mordecai had written to them.
24For Haman the Agagite, the son of Hammedatha, the enemy of all the Jews, had plotted against the Jews to destroy them, and had cast Pur (that is, cast lots), to crush and to destroy them.
25But when it came before the king, he gave orders in writing that his evil plan that he had devised against the Jews should return on his own head, and that he and his sons should be hanged on the gallows.
26Therefore they called these days Purim, after the term Pur. Therefore, because of all that was written in this letter, and of what they had faced in this matter, and of what had happened to them,
27the Jews firmly obligated themselves and their offspring and all who joined them, that without fail they would keep these two days according to what was written and at the time appointed every year,