שׁוּחָ֣ה עֲ֭מֻקָּה פִּ֣י זָר֑וֹת זְע֥וּם יְ֝הוָ֗ה יפול־[יִפָּל־] שָֽׁם׃
Mulut perempuan-perempuan jalang adalah lubang yang dalam; orang yang dimurkai Yang Mahakekal akan jatuh ke dalamnya.
Sha'arei Teshuvah
And among the words of our Rabbis about the sense of hearing is, “A person should not allow his ears to hear idle matters, because they are the first of the limbs burned” (Ketuvot 5b). And about the one that audits a mouth that speaks vulgarity, it is stated (Proverbs 22:14), “The mouth of strange women is a deep pit.” One who is of the fearers of God and of the penitents should pay attention to all of this, in order to save his soul from the flame. And we have already written fine words about this matter in the Gates of Precautions of Caution (no longer extant).
Sha'arei Teshuvah
And the fifth section: Vulgar speech. Our Rabbis, may their memory be blessed, said (Shabbat 33a), “Anyone who speaks vulgarly - even if he was sealed for a decree of seventy years of good, it will be reversed to bad.” And Isaiah said (Isaiah 9:16), “That is why my Lord will not spare their youths, nor show compassion to their orphans and widows; for all are ungodly and wicked, and every mouth speaks vulgarity.” And on account of this, one who speaks vulgarly has a heavy iniquity and is ungodly and wicked. For he has abandoned and left shame and modesty, which are the famous traits of the holy seed (of Israel); and went to the paths of brazenness - which is the trait of the evil boors. Secondly - because he has profanced the Holy One of Israel, as it is stated (Deuteronomy 4:6), “and they will say, ‘Surely, that great nation is a wise and discerning people.’” But this one acted like the disgusting foolish ones that are distanced from the ways of the intellect, which is completely beautiful and also pleasant. And their foulness rises and their stink goes up, so every sage and understanding person surely despises and surely abominates them. And behold, he is profaning the tool of the intellect which is more precious than any beloved tool - as it is stated (Proverbs 20:15), “but wise speech is a precious tool.” And the punishment of one who listens to vulgar speech is great, since he does not seal his ear and does not separate from the words of vulgarity. And about him is it said (Proverbs 22:14), “The mouth of a forbidden woman is a deep pit; [He who is doomed by the Lord falls into it].”
Iggeret HaGra
I reiterate my request that you guide your sons and daughters with words of kindness and Mussar that will find a place in their heart. This is true especially if we merit to arrive in Eretz Yisrael, because one must be extra cautious to follow Hashem's ways there. Therefore, train them well, since one must work hard on one's speech and character traits, and only through good habits can we control ourselves (Shaarey Teshuvah). All beginnings are hard (Mechilta Yisro). But afterwards, one is worthy of praise (Mishlei 20:14). For the wicked person knows that he is taking the wrong path, but it is hard for him to change. But this is man's main task, not to go after his desires, but (Tehillim 32:9) "to restrain himself with a bit and bridle when he is being groomed." Man must deprive himself until he dies, not by fasting or asceticism, but by controlling his mouth and desires. This is teshuvah. And this is the whole reward of the World-to-Come, as it is written (Mishlei 6:23): "For the commandment is a lamp and the Torah is a light" - but "the way to life is the rebuke that disciplines." And that is worth more than any amount of fasting and self-affliction! For every second that man controls his tongue, he merits some of the "hidden [by Hashem for the righteous] light," something which no angel or [other] creature can imagine (Midrash). And it is stated (Tehillim 34:13,14): "Who is the man who desires life, and loves days that he may see good? Guard your tongue from evil, and your lips from speaking deceitfully." This will atone for any sin and save one from Gehinnom, as we find (Mishlei 21:23): "He who guards his mouth [from too much eating and drinking] and tongue [from idle words] guards himself from trouble." Also (ib. 18:21): "Death and life are in the power of the tongue." Woe to one who gives away his life for one word! Then what advantage is there to one who has a tongue (see Koheles 10:11)? And, "Everything has a cure except, etc." It is most important to refrain from speaking words of praise about anyone. How much more so does this apply to speaking ill of anyone! Why must one speak about others? "The mouth that speaks strangely is a deep pit; he who angers Hashem falls into it" (Mishlei 22:14).