'Confirm' in the Bible

"Any vow and any sworn oath of a pledge to inflict on herself, her husband can confirm it or her husband can nullify it.

But you must remember Yahweh your God, for he [is] the [one] giving you strength to acquire wealth in order to confirm his covenant that he swore to your ancestors {as it is today}.

[It is] not because of your righteousness and because of the uprightness of your heart [that] you [are] coming to take possession of their land, but because of the wickedness of these nations Yahweh your God [is] driving them {before you}, and in order to confirm the {promise} that Yahweh swore to your ancestors, to Abraham, to Isaac, and to Jacob.

(Now this {was the custom in former times} in Israel concerning the kinsman-redemption and transfer of property: to confirm the matter, a man removed his sandal and gave [it] to his fellow countryman. This [was] the manner of attesting in Israel.)

So then, Yahweh God, the word that you have spoken concerning your servant and concerning his house, confirm it forever, and do just as you have promised.

While you are still there speaking with the king, I will enter after you, and {I will confirm your words}."

Then Benaiah the son of Jehoiada answered the king and said, "Amen! So may Yahweh, the God of my lord the king, confirm it!

So Queen Esther the daughter of Abihail and Mordecai the Jew wrote in full authority to confirm this second letter of Purim.