Esther 8:10-13

He wrote under the name of King Xerxes and sealed the order with the royal signet ring; he sent out the bulletins by couriers on horseback, riding the fastest royal steeds bred from the royal stud. The king’s order authorized the Jews in every city to arm and defend themselves to the death, killing anyone who threatened them or their women and children, and confiscating for themselves anything owned by their enemies. The day set for this in all King Xerxes’ provinces was the thirteenth day of the twelfth month, the month of Adar. The order was posted in public places in each province so everyone could read it, authorizing the Jews to be prepared on that day to avenge themselves on their enemies.