'Confirm' in the Bible

Then Esther the queen, the daughter of Abihail, and Mordecai the Jew, wrote with all authority to confirm this second letter of Purim.

to confirm these days of Purim in their appointed times, as Mordecai the Jew and Esther the queen had decreed, and as they had imposed upon themselves and their descendants, in the matter of the fastings and their cry.