It is vital that people recognize that the metzora, spiritual leper, is impure, and, as a result, people will veer away from him. The Sefer HaChinuch explains the source/root of this mitzvah. (Not a reason, because reasons are not given for mitzvos. Mitzvos are mandated, and only Hashem knows the true reason.) The metzora should take his distancing from his people as an example for his neshamah, soul. A person is distanced from all good as a result of his sin, in order that he be inspired to repent from his evil way. As a result of his slanderous speech he caused man to be separated from his wife, friend from friend. Therefore, he, too, must be separated. Let him feel the pain that he has caused others.
As a general principle, Hashem punishes (and rewards) middah k’neged middah, measure for measure. Every bad event that happens to man does not “just happen.” It happens because, as a result of his sin, Hashem removes His guardianship from him until he receives the fitting punishment that is consistent with his sin. In other words, by our actions we are the direct cause of our punishment, which will be measure for measure. If we would only acknowledge and delve into what happens to us, we would likely deduce what it is that we have done to incur such punishment. This is where middah k’neged middah is quite helpful. Furthermore, when a person acts positively in a specific manner, he will be reimbursed by Hashem in a like manner. Thus, if one is in need of a yeshuah, salvation, the positive way he acts towards others will be viewed by Hashem as a catalyst for reward in the area commensurate with his positive actions. The following story is but one example of the immediate effect of middah k’neged middah. (While this is certainly not the first story of its nature, it is astonishing how the middah k’neged middah occurred almost immediately.)
Moshe was a wonderful boy who was otherwise perfectly healthy and well developed, both physically and emotionally. I say “otherwise” because, at a young age, Moshe suddenly began to stutter terribly. His parents visited doctors, therapists, psychologists – all to no avail. No one was able to relieve Moshe of his stuttering. Nothing worked until, one time, when Moshe’s mother attended a wedding. During the meal, when she was sitting at a table with a group of women, one of the women, unprovoked and clearly unjustified, embarrassed her publicly. The entire table just sat shocked, waiting for a reaction. There was none. She just let it slide by as if nothing had occurred, totally ignoring the woman’s vitriolic, baseless slander. The strength of character which Moshe’s mother evinced was incredible. She must have wanted to dig a hole under her chair and slide down into it. She did not, acting as if nothing had been said.
A couple of hours later, Moshe’s mother returned home to be met by her son, Moshe, who was preparing for bed. He asked her about the wedding, and she almost fainted. He did not stutter! He spoke clearly, enunciating every word properly – no gaps, no stuttering. She did not believe her own ears. The unbelievable transformation of her son’s speech came immediately upon the heels of her restraining her response to the woman who had slandered her. She suffered in silence. Hashem rewarded her with sound – the beautiful sound of her son’s voice.
We have no doubt that one who refrains from responding believes that Hashem has a reason for presenting this situation. The person who committed the slander is a vehicle of Hashem. A reactive response achieves nothing but a quick descent to that person’s nadir. The person who slandered Moshes’ mother clearly had a severe problem. Hashem used that person to send home a message, and, as a result, she became a better person. In such a situation, one should show that he believes in Hashem and that he acknowledges that He is testing his compliance to His message. Moshe’s mother listened, and now she is able to listen to the unimpeded sound of her son’s speech.