'Seal' in the Bible

Then the king removed his signet ring from his hand [that is, the special ring which was used to seal his letters] and gave it to Haman, the son of Hammedatha the Agagite, the enemy of the Jews.

The king's scribes were summoned on the thirteenth day of the first month, and all that Haman commanded was written to the regional authorities of the king, to the governors who were over each province, and to the officials of each people. This order was translated in the name of King Ahasuerus into the language of each province and bore the seal of the king's signet ring.

Write ye also for the Jews, as it liketh you, in the king's name, and seal it with the king's ring: for the writing which is written in the king's name, and sealed with the king's ring, may no man reverse.