At the very end of Parashat BeHa'alotecha, the Torah retells the episode of Miryam becoming afflicted with Tzara'at. The common cause of the ailment is committing the sin of Lashon HaRa, speaking badly about one’s fellow man. Lashon HaRa is the direct cause of Miryam being afflicted with the disease. The Pasuk states, "VaTedabeir Mir’yam VeAharon BeMoshe Al Odot HaIshah HaKushit Asher Lakach," "And Miryam and Aharon spoke about Moshe on the topic of the Kushite woman whom he took (for a wife)" (BeMidbar 12:1). The taking of an Ishah Kushit is seen as a negative action, because, as explained by the Midrash Agadah, Nashim Kushiot are known to be promiscuous women. Miryam further shows her contempt for Moshe when, in the next Pasuk, "VaYomeru HaRak Ach BeMoshe Diber Hashem HaLo Gam BaNu Dibeir VaYishma Hashem," "And they (Miryam and Aharon) said, 'Did Hashem speak only with Moshe? Did He not also speak with us?' And Hashem heard" (BeMidbar 12:2). The very next Pasuk states that Moshe is more humble than any other person. The Torah informs us of Moshe’s extreme level of modesty before he confronts Aharon and Miryam about their transgression and before punishing them. A question arises from this seemingly peculiar order of events. Why would the Torah's immediate reaction to Moshe’s marital pursuits be to defend his modesty? It seems based on the simple understanding of the Pesukim that in no way is Miryam attacking or bringing into question Moshe’s modesty!
The answer to this question comes from the notion that the two ideas of Mitzvot and modesty are inherently connected. We know that during the period of Sefirah between Pesach and Shavu’ot, the Halachah as codified in the Mishnah Berurah restricts us from, among other things, cutting our hair and from dancing. The reason for these prohibitions is to mourn the loss of the 24,000 students of Rabi Akiva. We know based on the Gemara that while they were quite adept in Torah they had one fatal flaw: they did not have proper respect for each other. What caused them to be so disrespectful of each other? The BeReishit Rabbah (61:3) explains that the disrespect emerged out of the competitiveness that was in the Beit Midrash. Each student felt the need to be more scholarly than the other and that advancement in Torah for his contemporary was a setback to his own. Each student felt the need to have the Kavod of being the top pupil of Rabi Akiva. As a result, they were very disrespectful to each other. This desire to have the honor of the top pupil emerged from the lack of modesty that the students had. A modest student would not strive to be the noted Talmid in the Beit Midrash, but rather would strive to become as learned as possible and to be part of the Kehilah. Therefore, because of the students’ lack of modesty, they were punished with death. The lesson which we learn from the tragedy of Rabi Akiva’s students is that one can be a true Tzaddik and Talmid Chacham only if one is modest as well.
This idea can be applied to the episode with Miryam in our Parashah. The Torah could have responded to Miryam's Leshon Hara by immediately defending Moshe regarding the issue of the Ishah Kushit. Instead, it defends his modesty. The reason for this is that when someone is modest, he must also be a Tzaddik. We know this because only a Tzaddik is referred to as modest. Therefore, the Torah is not only defending Moshe in that specific instance, but is also sending the message to Miryam, and, by extension, to all of the Bnei Yisrael, that the true mark of a Tzaddik is his modesty. Many people can refrain from doing Aveirot at a specific time. To be a true Tzaddik, one must also have the trait of modesty. The message is that one who solely involves himself in Mitzvot is not a true Talmid Chacham. One must also be modest. Once a person has reached the level at which he combines all of these attributes, he can be classified as a Tzaddik.