'Rules' in the Bible

Giving the force of law to these days of Purim at their fixed times, as they had been ordered by Mordecai the Jew and Esther the queen, and in keeping with the rules they had made for themselves and their seed, in connection with their time of going without food and their cry for help.

The order given by Esther gave the force of law to the rules about the Purim; and it was recorded in the book.