Musar su Deuteronomio 4:6

There is little point in looking for moral ethical messages in this portion when the entire portion is literally filled with such messages. In fact the same can be said of most of the Book of Deuteronomy. Moses' principal purpose in writing this book called משנה תורה, review of the Torah, was to ensure that the new generation would relive in their minds what the previous generation had actually experienced, and that they would draw the appropriate moral conclusions from all this and engrave it on their collective memories.

And the parable for this is about a man that wants to go to a city. And he is told that the path is confounded with thorns, snares and stumbling blocks. But because of his need for the place, he is not prevented from going. But if they would tell him that there is a lion on the path and a leopard constantly on it, he would then stop his feet from this path. Therefore King Solomon, peace be upon him, said (Proverbs 1:2), “For learning wisdom and reproof; for understanding.” Its explanation is [that] proper action and abandonment of sins is called wisdom, like the matter that is stated (Deuteronomy 4:6), “for that is your wisdom and your understanding.” But after he learns and know the commandments and what are the sins, he needs to study the disgrace of the sins, and the damage and the loss that comes with them - in order to distance his soul from them; to reprimand himself by remembering the punishments and to reprove others. And this knowledge is called reproof (mussar); and it is pleasant for those that give rebuke to study this.

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].”