Shemirat HaLashon שמירת הלשון

Another possible reason for calling this [(guarding of the tongue)] a "craft" is that just as all crafts require study until they are truly learned, so is it with speech. A man may not say to himself; Why belabor myself with guarding my tongue to know all the aspects of its functioning if I can acquire a natural muteness and this can suffice [for all exigencies]! For it is not so. For the proper response changes often according to the circumstances [as explained in Chafetz Chaim, Part One, Chapter VIII:5, and in Part Two, in several places]. Therefore it is necessary to learn and to know the categories and particulars of speech in order to know how to conduct oneself properly in the craft of that "muteness."

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?"

And Chazal have said (Avoth 1:16): "All of my days I [R. Shimon] have grown up among the sages and I have found nothing better for the body than silence." That is: "I have grown up among the sages and chosen from their comely and holy traits, and the trait of silence was the best of all." Or: "Even though they were learned sages, and their speech was not, G-d forbid, of empty things, still I found that the best thing of all for the body, aside from words of Torah, was absolute silence." As far as the stress on "the body" is concerned, the meaning is: A man, though he be wise and perfect in his soul, as were the companions of R. Shimon, still in point of the matter "clothing" the soul [i.e., the body], it is almost impossible that all of his words be properly limited — wherefore, silence is best of all. And if in the generation of R. Shimon, whose tongue was habituated to speak in wisdom, so that even if it were not entirely guarded it would not swerve from its path, G-d forbid, still, he said that silence was best of all — what should we, the [mere] "hyssop of the wall" do, all of whose thoughts and speech, from our youth on, are only of vanity and emptiness? If we do not muzzle our mouths with the rein of silence with all of our strength, then certainly the tongue will do as has been its wont from early youth, and the loss [sustained by speaking] will far outweigh the reward.

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.

Silence becomes sages; how much more so, fools. (Avoth 3:17): "A fence for wisdom is silence." "Silence is the universal cure." And guard your tongue like the pupil of your eye. (Mishlei 18:7): "The mouth of a fool is destruction to him, and his lips are a stumbling-block to his soul." And (Ibid. 21:23): "One who guards his mouth and his tongue guards his soul from suffering."

And if you are sitting in a company, it is better that they say to you: "Speak. Why are you so silent?" than that you speak and your words be so tedious to them that they say to you: "Be silent!"

And it is written (Michah 7:5): "From her who lies in your bosom, guard the doors of your mouth." Scripture has hereby intimated to us that the mouth is like a door. And just as the door of a house has a time to be open and a time to be closed (for if it is always open everything in the house will be lost), so the doors of your mouth have a time to be open — to words of Torah and other essential things, and a time to be closed — to other things.

And a man must know that speech is the "beloved of all the beloved," for through it the form of man is perfected.

Therefore, just as one who has silver, gold, and pearls makes an enclosure within an enclosure to guard them and hides them in his innermost chamber in a special chest, so, even more, must he make an enclosure within an enclosure for his mouth; and that is, through the trait of silence.