Musar su Proverbi 4:22

And in Sifrei, Parshath Ekev we find (Mishlei 5:16): "'Then your springs [of Torah] will spread outwards': Words of Torah are compared to water. Just as water lives forever, so, words of Torah live forever, as it is written (Ibid. 4:2): 'For they are life to him who finds them, and to all of his flesh, healing.' And just as water raises the unclean one from his uncleanliness, so, words of Torah raise one from uncleanliness to purity, as it is written (Psalms 19:10): 'The fear of the L-rd is pure.' [And, just as water purifies a man, though the uncleanliness has spread through all of his limbs, so, Torah purifies a man from the uncleanliness of his sins, even if it has spread throughout him, from the soul of his foot until his head. And just as a man is not purified until the water rises over all of his limbs, and there be nothing intervening between his limbs and the water, so, he must subject all of his body and his limbs, in truth, to Torah, with nothing intervening, as it is written (Devarim 6:6): 'And these words shall be … upon your heart']. And just as water restores a man's soul, so do words of Torah restore a man's soul from the way of evil to the way of good, as it is written (Psalms 19:8): 'The Torah of the L-rd is complete, restoring the soul,.' And just as water is free for the world, so is Torah free for the world, as it is written (Isaiah 55:1): "Ho! all who are thirsty, go to the water [of Torah]." Lest you say: 'Just as water has no valuation, so, Torah has no valuation; it is, therefore, written [to negate this] (Mishlei 3:15): 'It is more precious than pearls and all of your desires cannot be compared to it.'"

The reason is obvious: Speech is not a specific part of a man as his other limbs are, each one being of benefit in itself. But it is the generality of man and his completeness. And that is why, when he perfects himself by occupying himself with Torah, all of his limbs are amended. For it reposes upon them a spirit of holiness to vivify them and to sustain them in this world and the next. As Chazal have said: "If one's head ails him, let him study Torah, as it is written, etc. If his throat ails him, let him study Torah, etc. If his whole body ails him, let him study Torah, as it is written (Mishlei 4:22): 'And to all his flesh it is healing.'" And the opposite, G-d forbid — by forbidden speech, he harms and defiles all of his limbs, and each and every limb falls from its eminence through this. And what advantage is it to them that their master lives and speaks if only to render din and accounting!

A piece of good advice for guarding the tongue: Even if he has already become habituated to it [(i.e., to a certain kind of lashon hara)], G-d forbid, and his yetzer has overcome him in this area, so that he himself does not "feel" the lashon hara that issues from his mouth, still he should not despair, but he should rest assured that by reviewing the din several times, a transformation will take place and the thing [i.e., the din] will become fixed in his nature, and, in the end he will "feel" [i.e., he will be sensitive to] every [article of] speech that leaves his mouth; and even if it be only the "dust" of lashon hara, he will feel it with his tongue at that time. For the Holy One Blessed be He has implanted in a man the faculty of "feeling" [i.e., sensitivity]. And He has done it in such a way that he feels it more when the "thing" comes in contact with his tongue. (This is similar to what Chazal have said (Chullin 17b): "The master examined it [(the slaughtering knife for kashruth)] with his mouth.,") And this faculty is of great avail in the learning of Torah, so that when one brings the thing [(what he is learning)] from his mouth to his tongue, its correctness is "tested." As Chazal have said (Eruvin 54a) on Mishlei 4:22: "For they [(words of Torah)] are life lemotzeihem"… to those who utter them ['lemotzi'eihem'], with their mouths." And the same [phenomenon] holds true for all aspects of speech; but it is only because of his great habituation to superfluous speech and [his tendency] to pay no heed to it that this faculty of his has become greatly weakened. But if he follows our advice (And he certainly will be attentive to what he says from that time on), this faculty of feeling will gradually strengthen itself in him, little by little until it reaches ifs full development.