Musar zu Kohelet 6:7

Especially so, when the soul finds no satisfaction whatsoever from all the pleasures of this world. This is what our sages teach us in Midrash Kohelet: "'but the soul will not be fulfilled' (Kohelet 6:7) - What is this analogous to? To the case of a common peasant who married the king's daughter. Even if he brought her all that the village possessed, it would be as nothing to her. For she is the king's daughter. So too with the soul, if you would bring to her all the pleasures of this world, they would be like nothing to her. For she is from higher worlds" (Kohelet Raba 6:7).

Therefore, I exhort you to train yourself to sit as much as possible, because the sin of the tongue is the most severe, as our Sages said (Tosefta Pe'ah 1): "These are the things...and lashon hara is equivalent to them all." I don't have to elaborate on this most serious sin of all. "All man's toil is for his mouth" (Koheles 6:7). Our Sages said that all man's mitzvos and teachings are not enough to counterbalance what comes out of his mouth. "What should be a man's pursuit in this world? He should be silent" (Chullin 89a). One must seal his lips as tight as two millstones. Idle words are like powerful weapons which can reach from one end of the world to the other. Now, this is true concerning mere excessive speech. Where forbidden speech is concerned - e.g. lashon hara, mocking, swearing, vowing, fighting and cursing - especially in the synagogue, and on Shabbos and Yom Tov - for every utterance of this type it is impossible to imagine the pain and suffering one will receive (Zohar)! No word is lost; everything is recorded. Winged beings attach themselves to everyone, recording all they say. "For a bird of the skies may carry the sound, and some winged creature may tell the matter" (Koheles 10:20). "Let not your mouth cause your flesh to sin, and do not tell the messenger that it was an error. Why should G-d be angered by your speech and destroy the work of your hands?" (ibid. 5:5). Purchase all your needs through a messenger, even if this would cost two or three times as much. "Is there a limit to what G-d can provide?" (Bamidbar 11:23). Hashem feeds all creatures, from the greatest to the smallest (see A.Z. 3), and provides all their needs. And on Shabbos and Yom Tov do not speak at all about things that are not urgent, and be brief even with what is important, for the Shabbos is very holy and our Sages barely permitted the exchange of greetings on it (Yerushalmi Shabbos, and Tosfos Shab. 113). See how strict they were concerning even a single expression! Continue to give great honor to the Shabbos as when I was there. Do not cut back [on your Shabbos] expenses, since "Man's entire sustenance [for the year is fixed for him from Rosh Hashana to Yom Kippur,] except [the expenditure for Sabbaths and Festivals,] etc." (Beitzah 16a).

And all that a man speaks with his mouth, all is written down above, as we find in the Midrash Rabbah, Tetze 6 on Koheleth 5:5: "Do not allow your mouth to sin against your flesh, etc." What does this mean? When the mouth speaks lashon hara it sins against the body, causing it to be smitten. Thus: 'to sin against your flesh' — the mouth sinning against the flesh. What is the intent of 'Do not say before the angel: "It is a mistake"?' Do not say: 'I shall go and speak lashon hara and no one will know.' The Holy One blessed be He says: "Know that I am sending an angel, and he will stand at your side and write down all that you are saying against your friend." As stated by the GRA in his book, Alim Litrufah: "He will bring all into judgment; all talk, and not even small talk will be lost. Therefore, I exhort you to train yourself as far as possible to sit alone, for the sin of the tongue encompasses all, as our sages of blessed memory have said: 'These are the things … and lashon hara against all.' And what need is there to elaborate on this sin, which is greater than all? Our sages of blessed memory have said: 'All of a man's toil is with his mouth' All the mitzvoth and learning of a man do not suffice for what he utters with his mouth. (Chullin 89a): 'What is a man's craft in this world? Let him make himself mute and close his lips like two millstones, etc.' And every "slinging" [of the soul after death], all (comes from) the breath of idle words. For every vain utterance, he [i.e., his soul] must be slung from one end of the world to the other. All this, for superfluous talk. But for forbidden talk, like lashon hara and levity and oaths and vows and quarrels and curses, especially in the house of prayer and on Sabbaths and festivals — for this, one must descend deep into Sheol. And it is impossible to conceive of the greatness of the suffering and the anguish that one must undergo for one utterance. And not even one word is left unwritten. [Heavenly] informers accompany each man at every moment and write down each and every word. (Koheleth 10:20): 'For a bird of heaven will carry the voice, and the winged one will tell the thing.' 'Do not allow your mouth to sin against your flesh, and do not say before the [recording] angel that it is a mistake,' etc." And he himself afterwards becomes a "chariot" to the unclean "shell" called "lashon hara," as it is written in Sefer Charedim 3:4.