“And the Jews smote all their enemies with the stroke of sword, slaughtering and exterminating; and they did to their enemies as they wished.” (Esther 9:5)
The words: ויעשו בשנאיהם כרצונם - “They did to their enemies as they wished”, seem superfluous; since the Jews had the upper hand, obviously they did as they wished?
A wealthy father who had an only son whom he loved very much instructed the executor over his estate: “When I die, give my son as much as you want from the estate and keep the rest for yourself.” The greedy executor kept 95% for himself and gave 5% to the son. The son, very upset and unable to believe that this was really his father’s intention, called the executor to a Beis Din. The rabbis listened carefully and ruled that the executor was to give 95% to the son and keep only 5% for himself, explaining to the executor that the father was indeed a very wise man. “His words were, ‘Give my son as much as you want, and the rest keep for yourself.’ Since you demonstrated that you want 95%, that must be the amount that the father wanted you to give his son.”
With the seemingly superfluous words the Megillah is telling us that, ויעשו בשנאיהם כרצונם - they did to their enemies exactly as they, the enemies, wished to do to the Jewish people. (Alshich, Manos HaLevi)
