1. And in the twelfth month – which is the month of Adar – on the thirteenth day of it, the word and law of the king were revealed to perform on that day that which was planned by the enemies of the Yehudim to conquer them. And it was turned around that the Yehudim conquered their haters.
According to Midrash Shmuel, the verse stresses that this occurred on the 13th of Adar because it was a miracle that so much time time passed since Sivan, and Achashverosh still hadn’t changed his mind despite the fact that the Talmud (Megillah 15b) describes him as fickle. He often changed his opinion on various important issues, including his feelings for his wife.
According to the Ben Ish Chai, the significance of the 13th because it shares the same gematria as echad (1+8+4=13) (“one”). Only H-Shem is One (Devarim 6:4), and the verse then teaches that H-Shem always saves His people.
Aside for Mordechai’s desire to send these letters in Sivan for the reasons mentioned above, the Yosef Lekach writes that Mordechai waited for Haman’s couriers to return from their original mission (Esther 3:13). Utilizing the same couriers would add legitimacy to Mordechai’s letter.
The Midrash (Bireishis Rabba 100:6) writes that H-Shem rewarded the gentiles for mourning Yaakov for 70 days (Bireishis 50:3) by giving them these 70 days between the 13th of Nisan and the 23rd of Sivan to do teshuva.
R’ Yehonason Eibshutz writes that a common calculation in the Torah is a day for a year, as when the Jewish people were punished (Bamidbar 14:17) with 40 years of delaying their entry into the Holy Land for their believing the spies who traversed the land for 40 days. Therefore, he writes, these 70 days were for the Jews to perform teshuva in gratitude for H-Shem’s saving their lives, which the verse (Tehillim 90:10) says lasts an average of 70 years.
Similarly, the Vilna Gaon explains that the Jews were scared about their fate for these 70 days to get an atonement for the 70 years of exile which they had caused upon themselves.
R’ Dovid Feinstein writes that these 70 days represented the 70 nations of the world were allowed to think that they were in control of the fate of the Jews.
9. And they called the scribes of the king at that time, in the third month – it is the month of Sivan – on the twenty-third of it. And they wrote all that Mordechai commanded to the Yehudim, and to the governors, and their underlings, and the officers of the states that are from Hodu until Cush – one hundred and twenty-seven states – each state according to its script and each nation according to its language, and to the Yehudim according to their script and their language.
The Talmud (Rosh HaShanah 7a) notes that there are different opinions as to the order of the months in the Jewish calendar. Accordingly, this longest verse in TaNaCh stresses that this event occurred in Sivan to teach that Sivan is the third month, making Nisan the first month. The year begins with Rosh Hashanah, in Tishrei, but the spiritual counting of the months for the purposes of holidays and seasons starts with Nisan.
Interestingly, the previous verses (Esther 8:1-8) and later verses (Esther 8:15) all occurred in Nisan, while these next few verses (Esther 8:9-14) occurred in Sivan. R’ Meir Zlotowitz explains that Achashverosh gave permission (Esther 8:8) to write these letters, so the text continues with the details of the letters, and will then backtrack to the chronology of the event.
The Lekach Tov notes that Sivan is the month of the holy day of Shavuos, when the Jewish people received the Torah. The merit of the Torah stood for Jews at this time.
Similarly, the Sfas Emes elaborates that the physical threat to the Jews had weakened, but the spiritual threat that snowballed into this potentially disastrous fate remained. Therefore, Mordechai joined the fight with H-Shem’s war against Amalek (Shemos 17:16) with a pledged renewal of the Jews’ commitment to the Torah.