Musar do Przysłów 18:21

There is yet another general tikkun distinctive for the trait of lashon hara, and that is Torah study, as stated in Arachin 15b: "R. Chamma b. R. Chanina said: 'What is the amendment for the speakers of lashon hara? If he is a Torah scholar, let him occupy himself with Torah, as it is written (Proverbs 15:4): 'The healer of the tongue is the tree of life,' and the tree of life is none other than Torah, as it is written (Ibid. 3:18): 'It [Torah] is a tree of life to those who hold fast to it.'" As to its being called "a tree of life" — "Death and life are in the hand of the tongue" (Ibid. 18:21). If so, one who speaks lashon hara acquires for himself eternal death, wherefore Scripture counseled one who wished to heal his tongue to eat from the tree of life, which is Torah, "and he shall eat [thereof] and live forever."

Chazal have also been very specific in their holy language in the term "in this world" [("What is the craft of a man in this world? Let him make himself mute, etc.")] That is, let a man not think: "I have already been habituated to this ["muting"] for more years than a craftsman to his craft, and I no longer need to devote my eyes and my heart to it so much" — wherefore Chazal have taught us that this is not so; but a man must train himself in this craft of making himself a natural mute all the days of his life, as the GRA has written in Alim Litrufah: "And until the day of his death a man must chastise himself, not with fasts and mortifications, but by putting a rein to his mouth and his lusts. And this is tshuvah [repentance], and this is all the fruit of the world to come, as it is written (Mishlei 6:23): 'For a mitzvah is a lamp; and Torah, light, and the chastisements of mussar [moral discipline], the way of life.' This is [worth] more than all the fasts and mortifications in the world. And Scripture states (Psalms 34:13-15): 'Who is the man who desires life, who loves days to see good? Guard your tongue from evil, etc.' And in this way all of his sins will be forgiven and he will be saved from the depths of Sheol, as it is written (Mishlei 21:23): 'One who guards his mouth and his tongue guards his soul from suffering,' and (Ibid. 18:21): 'Death and life are in the power of the tongue.' Woe unto him who puts himself to death for one particle of speech. And what advantage is there to the man of the tongue?"

One who is habituated to silence escapes many transgressions — flattery, levity, lashon hara, falsehood, and insult. For if someone shames and insults him, if he answers him, he will get a double portion. And thus does the wise man say: "I hear evil and keep silent." The other: "Why?" The wise man: "If I answer and retort to my shamers, I fear that I will hear insults more biting than the others!" Also, if one cultivates the trait of silence, everyone feels free to share his secrets with him. Since he is not disposed to speaking, he will not reveal them. In addition, he is not given to rechiluth. In this connection it is written (Mishlei 18:21): "Death and life are in the hands of the tongue." For a man does more [damage] with his tongue than with his sword. For [through scandal] a man can stand here and deliver his friend, who is far from him, to death, whereas the sword kills only at close range. Therefore, a man was created with two eyes, two ears, and two nostrils, but [only] with one mouth, to teach him to minimize speech.