Esther 3:5-7

And when Haman saw that Mordecai bowed not, nor did him reverence, then was Haman full of wrath. And he thought scorn to lay hands on Mordecai alone; for they had shewed him the people of Mordecai: wherefore Haman sought to destroy all the Jews that were throughout the whole kingdom of Ahasuerus, even the people of Mordecai. In the first month, that is, the month Nisan, in the twelfth year of king Ahasuerus, they cast Pur, that is, the lot, before Haman from day to day, and from month to month, to the twelfth month, that is, the month Adar.