Esther 9:27 (KJV)

But when Esther came before the king, he commanded by letters that his wicked device, which he devised against the Jews, should return upon his own head, and that he and his sons should be hanged on the gallows.

Wherefore they called these days Purim after the name of Pur. Therefore for all the words of this letter, and of that which they had seen concerning this matter, and which had come unto them,

The Jews ordained, and took upon them, and upon their seed, and upon all such as joined themselves unto them, so as it should not fail, that they would keep these two days according to their writing, and according to their appointed time every year;

And that these days should be remembered and kept throughout every generation, every family, every province, and every city; and that these days of Purim should not fail from among the Jews, nor the memorial of them perish from their seed.

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