Musar for Arakhin 30:16

We have also opened in this part an additional gate, the third gate, "The Gate of Torah," which subsumes all of the gates, as Chazal have said: "He who lacks this [Torah], what has he acquired? And he who has acquired this, what does he lack?" (And it [Torah], too, is of great benefit to the man who wants life. As they have said (Arachin 15b): "What is the amendment of the "man of lashon hara? If he is a Torah scholar, let him occupy [himself] in [the study of] Torah.") And in it will be explained the greatness of the reward of the man who sanctifies his speech with Torah, and the reward of him who dedicates his sons to Torah, and various other things that branch out of this. And because there will be in this part, with the help of the Blessed L-rd, many things that are essential for a Jew to know and to fulfill, it [this part] is especially beloved of me, and I have given it a name by itself. It shall be called "Shmirath Halashon" ["The Guarding of the Tongue,"] as per Mishlei 21:23: "One who guards his mouth and his tongue guards his soul from troubles."

The tenth principle of repentance is to reverse one's deeds. How does one do that? If he has been guilty of looking at indecent things, then let him conduct himself with lowered eyes. If he has been guilty of gossip, let him occupy himself with Torah (Arakin 15b). And with any limb with which he has sinned let him try to fulfill commandments (see Yalkut Judges, 42). And thus did our Sages say, "The righteous men in the very thing with which they had sinned appease God" (see Yalkut Hosca, 529). And more did our Sages say, "If you have committed bundles of transgressions, do in opposition to them bundles of good deeds. Feet which ran hastily to sin must now quickly run to do a good deed. A mouth which once spoke disobedience and rebellion now let his palate speak the truth and let him open his mouth with wisdom. Hands that spilled innocent blood, let him open his hand to the poor. Eyes that were haughty, let him be contrite and walk with lowered eyes. A heart that plotted wrongdoing, let him store up in his heart the words of the Torah" (Lev. Rabbah 21:5).