According to a Midrash, Achashverosh is upset at this point because, in the garden, Achashverosh remembered that Haman (as Memuchan) was responsible for Vashti’s demise (Esther 1:16).
The Dena Pishra adds that Achashverosh was upset that Haman was speaking to Esther behind his back. He even considered that if she pleads for his life, Achashverosh would still not listen to her.
The Yosef Lekach notes that Achashverosh took Haman’s silence as admission of guilt, based on this principle in the Talmud (Yevamos 87b) that people are expected to speak up for themselves when accused unjustly.
The Malbim writes that Achashverosh was angered that Esther seemed included in decree without his expressed agreement. The Malbim adds that this anger created an unsafe environment in the palace, despite its providing political and legal sanctuary.
The Ben Ish Chai writes that the Talmud (Shabbos 33a) teaches that dropsy and its attending discoloration affect people who are guilty of immorality. Thus, Achashverosh suspected Haman of immoral acts due to his face coloring.
R’ Moshe David Valle notes that Achashverosh could only think immorality was on Haman’s mind at a time like this if he so was inspired by H-Shem.
Perhaps some insight may be gained on this topic from the Talmud’s (Horiyos 10b) understanding of the story (Shoftim 4:17-22) between Sisera and Yael. There, Sisera is in mortal danger, and yet is easily seduced by Yael. Violence and immorality sometimes go together.
However, according to Midrash Shmuel, Achashverosh did not really think anything immoral was happening. In fact, he did not even accuse Haman of anything like that. Rather, H-Shem had the words come out of the king’s mouth to make Haman more nervous.
The Vilna Gaon writes that Achashverosh simply thought Haman intended Esther harm. Perhaps, this anger was pretense, and was Achashverosh’s method for ridding himself of Haman in the most politically expedient fashion. Interestingly, none of these answers explaining Achashverosh’s anger need be exclusive; the combined reasons create a massive, unappeasable anger that justifies the king’s next act.
12. And Mordechai returned to the gate of the king. And Haman was propelled to his house mourning, and with a covered head.
It seems doubly strange for the verse to say Mordechai returned to the palace, when our commentary on the previous verse made clear the Haman found Mordechai in the house of study. According to the Talmud (Megillah 16a) and the Midrash (Esther Rabba 10:6), the verse emphasizes that Mordechai returned to the king’s gate instead of into because Mordechai returned to wearing sackcloth and fasting.
Rashi’s explaining that Mordechai returned to mourning seems to not be his pashut pshat, simple explanation.
The Maharsha clarifies that Mordechai could not enter the king’s gate wearing sackcloth because of their rules of propriety in those days, so he could only come as far as the gate, itself. Therefore, Mordechai, having been mourning in sackcloth for the last several days could not be said to be returning to a place where he could not have previously been.
R’ Avigdor Bonchek explains that being paraded on a horse emboldened Mordechai to defy Achashverosh’s law by going to gate in sackcloth.
The Targum writes that Mordechai returned to serving on the Sanhedrin at this point, a position that is described in TaNaCh (see Bireishis 19:1, Devarim 21:19, Ruth 4:1) as being positioned “at the gate.”
The Midrash (Shemos Rabba 38:4) teaches that the verse says Mordechai returned because he is humble. There is a humility in accepting one’s place, as is said of Avraham whom the Torah (Bireishis 18:33) describes as having “returned to his place” after speaking with H-Shem.
R’ Henoch Leibowitz notes that the Torah (Devarim 30:8) promises us that H-Shem will return us to our Land only after we suffer from our enemies. Rav Leibowitz explains that the lesson is that a person’s prayer in times of rescue should be equal in power and intensity to that with which one prays in times of troubles. The very purpose of our troubles is to increase our attachment to H-Shem. The proper method for this is to follow Rabbeinu Bachya’s advice (on Shemos 2:23) when he says that one’s prayer is the most intense in times of difficulty and that, therefore, it is incumbent on a person to remember that feeling of intensity, and bottle up that feeling of pain in order to pray strongly in the brighter future that the troubles do not return. At our most desperate, we should try to encapsulate the emotion to use in better times.
He quotes R’ Naftoli Tropp, the Rosh Yeshiva of the Chofetz Chaim’s yeshiva in Radin writes that a famous piyut said on Yom Kippur calls us all dalim, poor. Even the rich should recall that all is H-Shem’s and they only have their riches only by the grace of G-d.
The Yosef Lekach writes that Mordechai usually wore sackcloth during davening, and then changed for court. At this point, Mordechai did not change because he felt his prayers were unsuccessful, and not answered. This is because his riding on a horse did not manifestly spell out the redemption of the Jews. The Jews were still threatened.
Rebbetzin Heller points out that, being G-d focused, Mordechai didn’t care if Achashverosh loved or honored him. This event did not change Mordechai’s humility.
The Sfas Emes writes that Mordechai still felt guilty about causing the threat to Jewish existence by refusing to bow down to Haman. True teshuvah comes from the feeling of being unworthy of kindness from H-Shem. He concludes that one should never be too confident in this.
The Iyun Yaakov points out that, on the political side, Mordechai had anticipated using his saving Achashverosh’s life as leverage when begging Achashverosh to save the Jews – not just a pony ride around town. Disappointed by the loss of his ace in the hole, Mordechai’s only remaining means to save the Jews is to pray to H-Shem.
The Ohel Moshe quotes the Brisker Rav, R’ Yitzchak Zev HaLevi Soloveitchik that in his reporting the goings-on to Esther earlier (Esther 4:5-16), Mordechai was unwilling to get out of his sackcloth for even one moment and even requiring Hasach as an intermediary because prayer and emunah are the main tools for salvation.
The Ohel Moshe also brings R’ Yehonason Eibshutz who quotes the Talmud (Brachos 5b) that a prisoner does not free himself. Somebody else needs to help somebody out. Similarly, Mordechai, once he sees himself rescued, returned to pray for the other Jews. Similarly,
R’ Dovid Bleicher of Novordok notes that Mordechai had his own needs met, but kept praying for the Jews because he had worked on himself to feel as if he was still under the threat of death.
The Midrash (Esther Rabba 6:12) states that a true Jewish leader does not stop fasting until the prayers are answered.
The Maharal notes that Mordechai was not satisfied by this honor because Achasherosh did not come to thank him, himself. He had no reason to think that Achashverosh felt actual gratitude. After all, as R’ Elie Munk points out in his commentary on Chumash (Vayikra 7:30), of all the offerings, the only one which the Torah describes as having to be brought “by his own hands” is the shelamim (peace offering) because it is brought as a way to thank H-Shem, and “when expressing one’s gratitude, it is proper to do it personally.”
Parenthetically, he also quotes this as the reason brought by Abudraham for the congregation to say the blessing of Modim (thanksgiving) during the repetition of the Amidah prayer, since the congregational leader cannot express the gratitude of another person.
The Maharal also says in a few places (Nesivos Olam) that simcha (joy) comes from shleimus (completeness). Here, too, Mordechai cannot be content since the Jews are still under the threat of annihilation, and are thus incomplete.
Perhaps the simplest explanation to why Mordechai returned to his place can be gleaned from a story told about R’ Yechezkel Abramsky. While discussing Megillas Esther with his rebbetzin, he asked her what Mordechai could have been thinking while riding on the horse. She answered, “This type of foolishness is for drunkards. I wish this will be over soon, so I can return to learning Torah!”