'Themselves' in the Bible

A copy of the edict was to be issued as a law in every province and as a proclamation to all peoples, so that the Jews would be ready on that day, to avenge themselves on their enemies.

In each and every province and in each and every city, wherever the king’s command and his decree arrived, the Jews celebrated with gladness and joy, a feast and a holiday. And many among the peoples of the land became Jews, for the fear of the Jews [and their God] had fallen on them.

the Jews established and made it a custom for themselves and for their descendants and for all who joined them, so that they would not fail to celebrate these two days as it was written and at the appointed time annually.

to establish these days of Purim [to be observed] at their appointed times, just as Mordecai the Jew and Queen Esther had established for them, and as they had established for themselves and for their descendants with instructions regarding their times of fasting and their lamentations (expressions of needing help).