The Yidden won the war, and they celebrated on the 14th and 15th of Adar, as it states (9:17-18), "He made it a day of feasting and gladness." These words are written in the singular tense. Why doesn’t the pasuk say, "They made it a day of feasting and gladness," since it was the entire Jewish nation who were celebrating their victory?
The Sfas Emes (Purim ב"תרנ) answers that ועשה refers to Hashem. "Hashem made it a day of feasting and gladness."
The Yidden rejoiced below, and Hashem was rejoicing in heaven. Every year, on Purim, Hashem rejoices and celebrates in heaven. Therefore, we should be happy, too. And if we try to be happy, Hashem will help us succeed.
Controlling Thoughts and the Power of Joy
Someone asked the Brisker Rav zt'l, "What can one do to control his mind and avoid forbidden thoughts?" The Brisker Rav replied, "Chasidim drink l'chayim and dance. They say it is a refuah for bad thoughts, and they are right."
One year, Reb Yeiva of Ostra’a wanted to be happy on Purim, but it was hard for him, as he was struggling financially. A joyous person arrived, they celebrated Purim together, and Reb Yeiva became happy. Reb Yeiva said this person was Mordechai HaTzaddik, the baal simchah on Purim. He comes to every Yid to make him happy on Purim.
Reb Yosef Tameshov zt'l (a student of the Chozeh of Lublin zt'l and of the Bnei Yissaschar zt'l) was singing Shoshanas Yaakov on Purim night in his father-in-law's home. The poritz came in and said that the singing was disturbing him. Reb Yosef immediately stopped singing. The next day, his father-in-law went to the poritz to apologize for his son-in-law's singing. The poritz didn't know what he was referring to. Reb Yosef Tameshov and his father-in-law understood that it was Haman who arrived in the guise of the poritz because it bothers Haman when Yidden are happy. Haman tries to make us sad on Purim, and Mordechai comes to make us happy.
It states (Esther 8:13), "For the Jews to be prepared for that day..." We read it עתידים, but it is written עתודים, which can be translated as flocks of sheep. The Maharsha quotes the Imrei Noam (HaKadmon), who explains that this hints that the Jewish nation should be dancing and jumping like sheep on Purim. They should be jumping for joy. This vort is also taught by the Maharam m'Rottenberg, and he says that there's a custom to write the ו"וא with horns on top of it (the תגין appear like horns) to allude to the jumping animals and our jumping for joy in praise of Hashem.
Pain and Joy Together
Purim is compared to Yom Kippur. The Piaseczner Rebbe zt'l (Eish Kodesh) explained that on Yom Kippur, we fast whether we feel up to it or not. Similarly, on Purim, we are happy, whether or not we feel up to it. (The Piaseczner Rebbe said this during the Holocaust.)
Reb Eliyahu Meir Bloch zt'l, Rosh Yeshiva Telz in America, was dancing happily with his students on Purim, in the year ד"תש. His students thought the joy wasn't sincere. "How could he be happy after what he suffered in the holocaust?" they said. Reb Bloch heard what people were saying, so he stopped the dancing, and the students gathered around him. He explained to them that the Jewish nation possesses the unique ability to be sad and happy at the same time. He proved this from the Chazal (Megillah 10:) that the malachim didn't sing shirah when the Yam Suf split because Hashem said, "My creations are drowning in the sea, and you are singing shirah?" Nevertheless, the Jewish nation sang shirah at this time. This is because a malach can only do one shlichus at a time. When he is happy and praising Hashem, he can't be sad simultaneously. But a Yid can do both. He mourns the loss of human life and rejoices in Hashem's salvation. Similarly, it is possible to be sad and broken from the holocaust and happy with Purim. There is room in a Yid's heart for both emotions.
Purim Miracle Because of Joy
Joy brings salvation, just as the Purim miracle occurred because of happiness.
Esther HaMalkah arranged parties. The Chasam Sofer zt'l says she was trying to free the Jewish nation from their tzaros through joy. She was upset when Mordechai wore sackcloth, as it states (Esther 4:4), "The queen [Esther] was greatly distressed; she sent garments to clothe Mordechai, and to remove the sackcloth from upon him..." The Chasam Sofer zt'l explains that she believed the way to be freed from their tzaros was through joy, not distress and mourning. She was upset that Mordechai took that path.
The Tiferes Shlomo asks, "Why did Esther send clothing to Mordechai? Did she think Mordechai didn’t have clothes to wear?" The Tiferes Shlomo answers that Mordechai and Esther debated how to annul Haman's decree. Mordechai followed the path of crying and mourning to rouse Hashem's pity and sympathy. Esther believed they would accomplish more with joy, so she sent Mordechai proper clothing. The Tiferes Shlomo writes, "When Esther heard Mordechai's loud cries for Klal Yisrael, she sent him clothing and asked him to remove his sackcloth. She implied that he should gird himself with joy and pray to Hashem with happiness. Mordechai disagreed because one needs to begin with humility and fear, and only afterwards with joy." They both agreed that joy was necessary. Their debate was only about how to begin. Esther believed they could start with joy, and Mordechai felt they must begin with remorse. However, they both understood that for the salvation to come it had to be through simcha.
The Megillah elaborates on the honor Mordechai received from Haman as Haman led him through the streets of Shushan. Why was this episode so important? And how was it part of the Purim miracle? The Tiferes Shlomo zt’l explains, "Mordechai was asked to ride the king's horse, dressed in the king's clothes. The people of the city sang and played music before him. All this was to make Mordechai happy. Immediately after Mordechai was filled with joy came klal Yisroel's salvation." All honor accorded to Mordechai was to get him to be happy, and when that happened, the salvation arrived.
The Gemara (Megillah 16.) says, "Haman took the king's clothing and horse and went to Mordechai. Mordechai began to daven, and Haman waited until Mordechai finished davening.” Then, Haman led Mordechai through the streets of Shushan with immense honor. Ben Yehoyada asks, why did Haman wait until Mordechai finished davening? Why didn’t he tell him right away that he came to honor him? Ben Yehoyadah answers, "Haman knew that Mordechai was davening with sadness, and Haman preferred it that way. Haman thought, 'If I interrupt his tefillah, he will have to daven again. And after hearing the good news [that I must honor him], he will daven with immense joy, and then it is likely that his tefillos will be answered.'"
At the first party, Achashverosh said (Esther 5:6), "What is your request? It will be granted to you. What is your petition? [Even if it be] until half the kingdom, it shall be fulfilled." What better time to express her plea for Bnei Yisrael? But Esther's only request was that Achashveirosh and Haman come to the second feast she would host the following day. Why did she push off pleading for the Jewish nation? This seemed like such an ideal time! Achashveirosh told her that just about whatever she would ask for, he would give her! The answer is that Haman was happy at the first party, as it states (Esther 5:9), "That day Haman went out joyous and exuberant." Esther knew she couldn’t bring down Haman when Haman was happy, so she pushed off pleading for the Jewish nation for the next day. The next day, Haman was sad, as it states (Esther 6:12), "despondent and with his head covered." That was an ideal time to bring about Haman's downfall. Indeed, Haman was hung that day. This teaches us that joy brings success and sadness leads to failure.