There is a custom of obliterating the name of Haman or making noise whenever his name is mentioned when the Megilla is read in shul. The Rama (Orach Chaim 690:17) endorses this custom and cautions against stopping or ridiculing customs, since they were established for a reason. He cites the verses "You shall wipe out the memory of Amalek" (Devarim 25:19), and "the name of the wicked will rot" (Mishlei 10:7). The proper fulfillment of this custom demands that we destroy any vestige of what Haman represents from our midst. The Gemara (Chulin 139b) links the name Haman to the passuk, "hamin ha'etz" (Breishis 3:11), wherein Hashem asks Adam, "Have you eaten from the tree from which I commanded you not to eat?" What is the connection between Haman and Adam's sin?
The Mishnas R' Aharon (Kotler, volume 1, page 103) explains. Haman tells his wife and friends about the glory of his wealth, his many sons, and his promotion by the king over all of his officers and servants, "Yet all this means nothing to me whenever I see Mordechai the Jew sitting" (Esther 5:11, 13) and not bowing to Haman as the king had commanded (3:2). Haman had everything, but was not satisfied because one Jew did not bow down before him. So, too, Hashem told Adam "From every tree of the garden you may eat, but from the tree of knowledge you may not eat" (Breishis 2:16, 17). Adam had everything, but was not satisfied because one tree was forbidden. Hence the connection between Haman and Adam's sin.
The lesson for us is to be satisfied with what we have. Many people have great success but are unsatisfied because of one unfulfilled wish. The pursuit of that elusive wish often leads to death, as befell Adam and Haman. It always prevents the happiness available to one who is satisfied with his portion (see Happy with our Portion, Purim 2014). When we make noise to wipe out the name of Haman, we eliminate envy and dissatisfaction from our midst.
The Maharal (Or Chadash 5:11) links the name Haman with the word "hamon - multitude" (see Breishis 17:5, Yechezkel 38:11). Haman achieved great wealth and had a multitude of sons (Megilla 15b). This caused him to be boastful, and ultimately led to his downfall. When we bang at Haman's name, we must eliminate any boastfulness from our midst. "Lest you eat and be satisfied and build good houses...increase your money and possessions. Your heart will become haughty and you will forget Hashem...You will say in your heart 'My strength and the might of my hand made me all this wealth'. Remember Hashem because He gives you strength to make wealth" (Devarim 8:12-18). Prosperity can lead to Haman like boastfulness. On Purim we must rid ourselves of this scourge.
Elsewhere (5:14) the Maharal links the final nun of Haman, whose numerical value is 50, with the gallows that Haman made to hang Mordechai, which were 50 cubits high. Haman made himself into a deity. Even Moshe was given only 49 of the 50 gates of wisdom (Rosh Hashana 21b). Haman deluded himself into thinking that he had godly qualities, represented by the 50th gate which was not given to man.
Moshe was the most humble person on earth (Bamidbar 12:3); notwithstanding his unparalleled greatness (Devarim 34:10), he was humble before Hashem and his fellow man. By contrast, Haman viewed himself as greater than all men and even attributed superhuman qualities to himself. This led to his destruction. The 50th gate of wisdom does not belong to man. By raising himself to the 50th level, he became a non-man, by his death, at the gallows 50 cubits high.
When we make noise during the Megilla, we must eliminate any hubris from our midst. We dare not question Hashem's commandments. Purim, the eternal holiday (Rambam Hilchos Megilla 2:18), commemorates our reacceptance of the Torah (Shabbos 88a) for all time. We must reject modern notions that some Torah laws are immoral because they run counter to post-modern values and sensibilities. At the same time, we must humble ourselves before others, following the example of Moshe and truly obliterating Haman from our midst.
The laws and customs of Purim celebrate our victory over Haman years ago. By internalizing and reinforcing the need to be rid of what Haman represents, as taught by Chazal, Rav Aharon and the Maharal, we can, and must, better ourselves as well.