In Megillas Esther, the unique phrase “pas’shegen ha’ksav” appears twice. The first time (3:14): “Pas’shegen ha’ksav … galui l’chol ha’amim l’hiyos asidim l’yom hazeh — A document … revealed to all nations to be prepared for this future day.” Rashi explains here: “Pas’shegen — Aramaic for a printed story.” The second time
(8: 8) adds: “and for the Jews to be prepared for this future day to take revenge on their enemies.” Here Rashi says: “Pas’shegen — an explicit letter.” Why does Rashi have two different translations of the same word?
A further look at the latter passuk shows that the request of Mordechai and Esther to recall the first letters that were sent is rejected. This is justified by the claim, “That which is written and stamped with the seal of the king cannot be retrieved.” The Rishonim ask: If so, how then does Mordechai manage to turn around the day for the benefit of the Jews? How is Mordechai allowed by Persian law to write new letters in defense of the Jews?
Look at Esther Rabbah (7:19) on the first verse of Pas’shegen ha’ksav. “Rabi Levi said the nevuah of umos ha’olam is closed. They don’t know if they will kill others or be killed themselves. This can be compared to a person on a long walk. He sprains his ankle. He says, ‘I so wish I had a donkey.’ Just then a Roman official comes by, saying, ‘My donkey just gave birth. I want you to carry my baby donkey.’ ‘I see my prayers were answered, just I didn’t ask properly whether I would carry or be carried.’ Such is the nevuah of umos ha’olam ‘to be prepared for this future day.’ They do not know if they will kill or be killed. But for Klal Yisrael, their nevuah is explicit (the second verse of Pas’shegen ha’ksav): ‘and for the Jews to be prepared for this future day to take revenge on their enemies.’”
First, we see that the Midrash views “pas’shegen ha’ksav” as not just a letter but a nevuah. Secondly, Rabi Levi is teaching that the nevuah of umos ha’olam is fundamentally unclear. It could be that Klal Yisrael will kill their enemies as opposed to being killed by them. But the nevuas Yisrael is explicit that the Jews will be victorious.
Now we understand that the first letter of the king was not invalidated. It was fundamentally unclear. Haman thought it meant that the Jews would be killed by their enemies. But Mordechai was able to give, through the second letter, an official, variant interpretation of the first letter that the Jews would kill their enemies.
Now we can appreciate the words of the Ibn Ezra (Esther 8:8): “One should ask: Why did Mordechai push so hard to kill his enemies? Certainly it would have been sufficient just to save the Jews. Know that Mordechai was a great Sage. Achashverosh said to him, ‘Do whatever you can to save your people, but a document issued and signed in my name cannot be retrieved…’ Therefore, Mordechai was forced to write the second document in this fashion of killing the enemies because of what had been written in the first document. The king had commanded Haman, his viceroy, to write a document and sign in the name of the king that the Jews should kill their enemies. Haman changed the wording so that the enemies should kill the Jews. When the king found out about the change that Haman had done, the king had him hung … and this is what is meant by the verse ‘v’nehafoch hu — the opposite occurred.’”
The words of the Ibn Ezra seem to say that Achashverosh was fundamentally in favor of the Jews at the very beginning of the Megillah. This is very far from pshat, where Achashverosh seems to be very much against the Jews, like Haman (see the beginning of Ch. 3 in pshat and further in Midrash there). Rather, if we push a little on the words of the Ibn Ezra and understand the Ibn Ezra like the Midrash quoted above, the matter becomes clear. Achashverosh wanted the first document written in his typical, vague fashion. This would lend itself to two alternate interpretations. Haman pushed and wrote it in a clear style. Mordechai is forced to write the second document in a fashion that fulfills and completes the first wishes of the king.
Now we can understand the terse comment of Rashi. Why does pas’shegen ha’ksav deserve a second explanation? Only at the end of the Megillah, like the Midrash above, does the second document become explicit in favor of the Jews, though the first document had such a potential before.