Esther 9:24-26

24because Haman, the son of Hammedatha the Agagite, the enemy of all the Jews, had plotted against the Jews to annihilate them, and had cast Pur (that is, the lot), to consume them and destroy them;

25but when Esther came before the king, he commanded by letter that this wicked plot which Haman had devised against the Jews should return on his own head, and that he and his sons should be hanged on the gallows.

26So they called these days Purim, after the name Pur. Therefore, because of all the words of this letter, what they had seen concerning this matter, and what had happened to them,