Esther 3:13 (ESV)

13 Letters were sent by couriers to all the king’s provinces with instruction to destroy, to kill, and to annihilate all Jews, young and old, women and children, in one day, the thirteenth day of the twelfth month, which is the month of Adar, and to plunder their goods.

The Persian Empire had a highly developed courier system, yet the empire was so vast that it would take around four months for the decree to reach its farthest corners.

Haman superstitiously clung to the date which had been indicated by the lot: the thirteenth day of the twelfth month. One can imagine the distress that the Jews would have suffered, as they awaited the day of their destruction. 

In order to ensure that the decree would be obeyed, Haman cunningly played on the people’s greed. He not only allowed them, but even ordered them to plunder the goods of their Jewish victims.