Why did she now agree to go to the king?
Malbim: Mordechai promised her that in any case, even if she will be killed, Hashem will save Yisrael. Their only benefit via her will be to bring the salvation earlier.
Why did she decree a fast only for the Jews in Shushan?
Vilna Gaon: In a few days, they cannot inform all the Jews in the world.
Why does it say both "Tzumu Alai" and "v'Al Tochlu"?
Arugas ha'Bosem (OC 180): "V'Al Tochlu" implies not to eat a k'Zayis; "Tzumu Alai" clarifies that the Shi'ur is k'Koseves (it is more than a k'Zayis 1 ). Aruch l'Ner (Yevamos 121b) - it is called a Tzom and Iruy until one eats k'Koseves. Therefore, they were able to eat a k'Zayis of Matzah.
Daf Al ha'Daf (Megilah 15a, citing Sifsei Tzadik, Purim 28): "V'Al Tochlu" is extra, to forbid eating any amount.
What is the meaning of "Sheloshes Yamim Laylah va'Yom"?
Yevamos 121b: They fasted three consecutive days, night and day.
Targum: [Fast for me] three days [during the day], and pray night and day. Shocher Tov 22:5 - if they fasted three days and nights consecutively, they would die! Rather, they were Mafsik during the day 1 .
Rivash (416 DH Mevu'ar): The Midrash means that the fasts were not consecutive, rather, e.g. Monday, Thursday and Monday. For each, they stopped eating during the day before the fast. Alei Tamar (Ta'anis 2:1, in the name of the Roke'ach) - the fasts were consecutive; they ceased fasting before sundown, to revive themselves. Aruch l'Ner (Yevamos 121b) - for the first fast (the 14th) they ceased eating during the day of the 13th. However, they ate during the nights after the fasts. Refer to 4:17:1:1*.
Which three days did they fast?
Rivash (416 DH Mevu'ar, according to Shocher Tov 22:5): The fasts were not consecutive. Ran (Ta'anis 7a, cited in Eliyahu Zuta 686:5) - there is a custom to fast three days, not consecutive, to recall Ta'anis Esther.
Maharsha (Megilah 15a), Torah Temimah (17): The 13th, 14th and 15th 1 .
Aruch l'Ner (Yevamos 121b): The night and day of the 14th, and the days of 15th and 16th.
Ya'aros Devash (2:9 DH v'Amru): There was a Beis Din in Yerushalayim that fixed the months. In Shushan, they mistakenly assumed that Adar was 29 days; really, it was 30 days. They thought that the last fast day was the 15th; really, it was the 14th, and the next night [which they thought is the second Seder night of Chutz la'Aretz] they fulfilled the Torah Mitzvah of Matzah. This was Hashgachah! (How did the mistake help? Had they known the true day, they would have eaten Matzah with intent for the Torah Matzah! Was it better that they accept to fast on what they believed to be Yom Tov? - PF)
What is "Asher Lo cha'Das"?
Rashi citing Megilah 15a: Until now, she was forced to be with the king. This time, she would go willingly.
Rashi: It is against the [king's] law to enter without being called.
Why did she say "v'Cha'asher Avadti Avadti"?
Rashi citing Megilah 15a: Just like I was lost from my father's house (orphaned), I am lost to you (as a wife, for now I go willingly to have Bi'ah with the Goy; I will be forbidden to you).
Rashi: Like I started to be lost, so I will go and die.
Malbim: When I will die and the king will kill me for transgressing his commands, there is no loss. Only I will die; the Jews will be saved in another way.
QUESTIONS ON RASHI
Rashi writes that Esther was lost from Mordechai, for now she goes willingly to have Bi'ah with the Goy. Mordechai could have divorced her, and remarry her later!
Tosfos (Megilah 15a DH k'Shem): A Get requires two witnesses 1 . Mordechai feared to do so, lest the kingdom find out that Esther was married to him.
Noda bi'Yhudah (2 YD 161): Indeed, he divorced her with Kesav Yado (refer to 4:16:8:1 and the note there) to avoid the Isur of Eshes Ish. However, he could not remarry her, for there is publicity to Kidushin 2 and Chupah.
Rashba (15a): He could have divorced her with a Get in Kesav Yado (his own handwriting). It does not need any witnesses! We do not question Agados. (Tosfos holds like R. Tam, who requires Edei Mesirah for every Get. The Rashba asks according to the Rif, who holds that signatures or Kesav Yado suffice. - PF)
A Kidushin document in Kesav Yado can be as covert as the Get! However, Chupah needs publicity, i.e. Birkas Chasanim, which requires 10 men (EH 55:1, 62:4). (PF)
