Parshat Shemot recounts the story of Moshe killing an Egyptian he saw striking a Jew and burying him. The next day, when trying to break up the quarrel between two Israelites identified by Chazal as Datan and Aviram, Moshe is rebuffed with the comment that because he killed an Egyptian, they do not need to listen to him. When Moshe found out that Datan and Aviram knew of his actions and might inform Paroh, he said “Achein Noda HaDavar,” “Behold the matter is known” (Shemot 2:14). Rashi says that the “matter” to which Moshe referred was the reason why Bnei Yisrael were in Galut in Mitzrayim in the first place. He realized that the two Aveirot responsible for the Galut were quarreling and speaking Lashon HaRa, the two sins Datan and Aviram were engaged in.
The Chafetz Chaim states in Shemirat HaLashon that the opposite of the Mitzvah of Limud Torah is the sin of Lashon HaRa. He explains that Lashon HaRa is so severe because the tongue, which could have been used for speaking words of Torah, is instead used to speak negatively about another Jew.
With these two ideas in mind, we can explain a famous Midrash. The Midrash states that in Mitzrayim the Jews were at the second to last of the fifty levels of Tumah, impurity, and at Kabbalat HaTorah they were able to reach the penultimate level of Kedushah. Why is it that they were considered so low during the Galut Mitzrayim whereas they were considered so great by Kabbalat HaTorah? It must be that they were at the lowest level of Tumah in Mitzrayim because they engaged excessivley in the worst possible Aveirah, Lashon HaRa. Conversely, they were considered at the highest level of Kedushah at Kabbalat HaTorah because they excelled in the greatest possible Mitzvah, Limud Torah. Thus, they were able to go from the lowest depths to the greatest heights because they completely changed how they used their speech.
Similarly, the Gemara in Yoma (9b) states that the second Beit HaMikdash was destroyed because of Sinat Chinam. The Chafetz Chaim, in his introduction to his Sefer Chafetz Chaim, explains this Gemara to include Lashon HaRa, the worst result of hatred, in the category of Sinat Chinam. Just like Bnei Yisrael were redeemed from Mitzrayim because they learned to use their power of speech for Mitzvot rather than Lashon HaRa, so too we, who are in Galut because of the sin of Lashon HaRa, will be able to end it and bring Mashiach by using our power of speech to do the Mitzvah of Limud Torah.