The Power of Every Word:
The Kedushas Levi expounds on the power of reading the Megillah and writes:
“One should be excited to hear the reading of the Megillah. When one hears it, he should ready himself to reaccept the yoke of Torah and mitzvos with joy. He should have in mind to purify all worlds, even this physical world, which is also purified by the reading of the Megillah. And he should rejoice to be able to create this purity and to fulfill the verse (Tehillim 104:34): ‘Hashem rejoices with His handiwork.’
One should have in mind that every word of the Megillah creates illumination and that every world creates a malach. One should be excited to think about how every word causes Hashem to rejoice and make a new angel.... Hashem rejoices when the Jewish people read the Megillah and thereby purify all worlds and all souls. Every word creates a nachas ruach for our Creator... and Hashem instills into our hearts a desire to serve Him with a full heart and to observe the mitzvos...”
Hisorerus While Hearing the Megillah:
The Gemara (Megillah 19A) states: “From where does it (the Megillah) starts? From the words ‘v’yemei Purim he’ileh’ (and these days of Purim). Rav Yehuda says: From the words “ish Yehudi” (a Jewish man).”
My grandfather, the Kretchnifer Rebbe zy”a (Kol Emunah, Pekudei 5760) explains that some people read the Megillah but are not inspired until they come to the pasuk of “ish Yehudi”, but they do begin to feel excited when they reach this verse. Anyone who feels like this is praiseworthy, as he is better than those who don’t feel inspired at all. Therefore, one should prepare himself in advance by studying Sefarim that create feelings of inspiration, so that he can feel excited during the reading of the Megillah and thereby bring about goodness for the world.
It Is Worthwhile to Hear the Megillah Even Once:
One year on Purim, the Satmar Rov zy”a emotionally announced, “It is worthwhile to come to this world just to be here for one Purim and to hear the reading of the Megillah. For this alone, it was worth it for the entire world to be created. If the world had been created for one reading of the Megillah, that would have been sufficient.”
Rectification for All Sins:
The Rebbe of Vildenick zy”a states that the root of the word “Megillah” is “gilui” (revealed). This indicates that reading the Megillah rectifies the all sins that are “revealed” (including “gilui arayos”).
Similarly, Sefer Ateres Yeshua (Nusach Hamegillah, Ois 52) writes that the reading of the Megillah can rectify all damage caused by our sins.
Meriting Children, Life and Sustenance:
The Gemara (Megillah 4B) states that “the eyes of the poor are uplifted with the reading of the Megillah.” Sefer Tiferes Shlomo zy”a explains that reading the Megillah creates hashpa’os that provide children, life and sustenance for Klal Yisroel. This is why there is a halacha (Shulchan Aruch, Orech Chaim 670:17) to spread out the Megillah like a letter, which symbolizes how these good influences spread around the world.
Sefer Ateres Yeshua (L’Purim, Ois 14) explains this Gemara by quoting Sefarim Hakedoshim (see Paneach Raza, Shaar Ha’amidah 20) that the first and last letters of the words “poseach es yadecha” (open Your hand) spell two names of Hashem that are auspicious for providing livelihood. The letters of the words “al mikrah Megillah” have the same numerical value as those letters, which indicates that reading the Megillah creates the same type of hashpa’os for parnassah.
Bringing About Salvations:
The Munkatcher Rebbe zy”a (Sefer Shaar Yissochor) writes that the word “Megillah” has the same gematriah as the word “mazla”. This is a hint that reading the Megillah can change a person’s mazel for the better and provide him with children, life and sustenance.