And the decree of Esther confirmed these matters of Purim,.... As a festival to be observed by the Jews in future generations:
and it was written in the book; either in this book of Esther; or in the public acts and chronicles of the kings of Persia; or in a book by itself, now lost, as Aben Ezra thinks, as many others are we read of in Scripture, as the books of the chronicles of the kings of Israel and Judah, &c.