Esther 8:8; Esther 8:10

8 "Now you write to the Jews as you see fit, in the king's name, and seal it with the king's signet ring; for a decree which is written in the name of the king and sealed with the king's signet ring may not be revoked."

10 He wrote in the name of King Ahasuerus, and sealed it with the king's signet ring, and sent letters by couriers on horses, riding on steeds sired by the royal stud.