Esther 3:4

3:4 And after they had spoken to him day after day without his paying any attention to them, they informed Haman to see whether this attitude on Mordecai’s part would be permitted. Furthermore, he had disclosed to them that he was a Jew.

Esther 9:27

9:27 Therefore, because of the account found in this letter and what they had faced in this regard and what had happened to them, the Jews established as binding on themselves, their descendants, and all who joined their company that they should observe these two days without fail, just as written and at the appropriate time on an annual basis.