Esther 9:20-26

Mordecai recorded these events and sent letters to the Jews near and far, throughout all the provinces of King Xerxes, calling on them to celebrate an annual festival on these two days. He told them to celebrate these days with feasting and gladness and by giving gifts of food to each other and presents to the poor. This would commemorate a time when the Jews gained relief from their enemies, when their sorrow was turned into gladness and their mourning into joy. So the Jews accepted Mordecai’s proposal and adopted this annual custom. Haman son of Hammedatha the Agagite, the enemy of the Jews, had plotted to crush and destroy them on the date determined by casting lots (the lots were called purim). But when Esther came before the king, he issued a decree causing Haman’s evil plot to backfire, and Haman and his sons were impaled on a sharpened pole. That is why this celebration is called Purim, because it is the ancient word for casting lots. So because of Mordecai’s letter and because of what they had experienced