Reb Noson Gestetner zt'l said in the name of the Chazon Ish zt'l, "There are two things that one never regrets doing: (1) Learning Torah, (2) Being silent." You will never regret learning Torah. The time you spend learning Torah is among the best moments of your life. And you will also never regret being silent. As one wise person said, "Before I speak, I rule over the words. After I speak, the words rule over me." Many machlokes are avoided and prevented by being silent.
By the machlokes of Korach, Korach had 250 heads of the Sanhedrin with him. These great scholars sided with Korach and supported him. They claimed that Korach was right for making the machlokes. So, how could a regular person living at that time know who was right and who was wrong? Was Moshe right or was it Korach? A gadol once replied that the test is simple and easy. You stand on the side and see who is silent. By every machlokes, the one who is quiet is the one who is correct. This rule is so true, even simple people should know it. And following this test, they would know that אמת ותורתו אמת משה, Moshe was correct, and Korach was wrong, because Moshe was the one who was silent by this machlokes. A hint to this concept is in the Gemara (Kiddushin 71:) "The silent people in Bavel are the ones who have good yichus."
It states in Avos (1:16-17) מן והסתלק רב לך עשה הספק, "Choose a Rav for yourself and avoid doubts." This can be translated to mean that one should not have any doubts who is the Rav, who are the true tzaddikim. A person might ask, "But I don't have ruach hakodesh, how can I know who are the true tzaddikim?" To answer this, the next Mishnah states, אמר יותר טוב לגוף מצאתי ולא החכמים בין גדלתי ימי כל ,שמעון 'ר משתיקה, "My entire life I was raised among chachamim, and I didn't find goodness for the body more than silence." He was saying that if you want to know who the true tzaddikim are, check and see who is silent by a machlokes. They are the righteous ones. They are the true tzaddikim whom Hashem chose to lead the nation.
Once, someone came to Reb Naftali Amsterdam zt'l and told him that his shalom bayis had dissolved, but due to the circumstances, he wasn't able to divorce his wife. Therefore, he asked Reb Naftali Amsterdam to sign on the document of היתר רבנים מאה, the leniency of one hundred rabbanim.
As this man spoke with Reb Naftali, he began saying lashon hara about his wife. Reb Naftali said, "People are so funny. They seek a רבנים מאה היתר, to permit something that isn't forbidden from the Torah. (It isn't a Torah prohibition to marry another wife, it is a cherem.) But lashon hara is forbidden from the Torah, and people speak lashon hara freely, without seeking any היתר, permission." People think everything is permitted when it comes to machlokes and lashon hara. Fortunate are those who train themselves to be silent. They don't answer back, and they don't speak lashon hara behind other people's backs. This will solve and remove many machlokes.
