Musar su Genesi 8:21

... And on this the Torah says (Exodus 13:7) "there will not be seen and there will not be found" - it will not be seen b'maaseh (in action) and will not be found b'machshava (in thought), rather one should anul it in his heart. The mitzvot have 3 categories: mitzvot of speech, of the heart and of action, as it is written (Deuteronomy 30:14) "in your mouth and in your heart to do it". Comes the Torah (instructing us) to anul it in the heart, corresponding to the mitzvot which are dependent on the heart. Comes the 'kabbalah' (instructing us) to eradicate it from the house or to burn it, corresponding to the mitzvot of action. And to say 'kol chamira', corresponding to mitzvot of speech. In this way the 3 categories of mitzvot are fulfilled through the prohibition of chametz, teaching you that the prohibition of chametz incorporates all the mitzvot... Just as the 'kabbalah' comes (instructing us) to eradicate chametz and (livdok) to check the house in nooks and in cracks, so too we are obligated to search and check the chambers of our inner being for bad (machshavas) intentions and bad (hirhurim) thoughts. Just as bedikat chametz (checking for chametz) is not valid by sunlight, nor by moonlight, nor by the light of a torch, but only by the light of a candle, so too the bedikah (checking) of the yetzer hara must be by the light of the neshama (soul) which is called 'ner' (candle), this is what is written (Proverbs 20:27) "the candle of Hashem is the soul of man, which searches the chambers of one's inner being.

Chapter 4 - How a person can accustom himself with the trait of understanding (binah): Understanding is repentance. And this is that one [should] repent - as there is nothing as important as it, since it repairs every defect. And like it is the way of Understanding to sweeten all of the judgments and to nullify their bitterness, so [should] a person repent and fix every defect. And one who ponders repentance all of his days causes Understanding to shine upon him all of his days. 'And it comes out that all of his days are in repentance' - which is [to say that he] is including himself in Understanding, which is Repentance. And [so] the days of his life are crowned with the secret of the Highest Repentance. And see, that [just] like Repentance has the root of all that is in existence in it through the secret of the Jubilee, and behold the root of the external forces - [which] is the secret of the River Dinur which is included in the holiness of the secret of the severities - is [also] rooted There and extends from There and this extension is called the extension of the burning fury, but the extension returns to its Source in the secret of "And the Lord smelled the pleasant smell" (Genesis 8:21), and the judgments are sweetened and the fury is stilled, 'and the Lord relents of the evil'; so [too] does a person do this secret with the secret of his repentance.

And, in truth, this is a great error. For if so, why did the Torah command this [(abstention from lashon hara)] by a negative commandment? Is it not known that "the Holy One Blessed be He does not deal despotically with His creatures"? The Torah, then, should have included this only in the class of middoth [desirable character traits], like other holy middoth, that are addressed only to unique individuals, [and not as a mitzvah]. But certainly the Creator of man put it in the power of each and every Jew that if he only puts his eyes and his heart to his ways he can avoid this [(speaking lashon hara)]. As we find in Sifrei, Parshath Ha'azinu (Devarim 32:4): "He is a G-d of trust, without wrong." That is, He did not create men to be reshaim, but to be tzaddikim. (For if not so, there is wrong, G-d forbid, in the ordinance of the Blessed One in the punishment that He metes out to them afterwards.) And thus is it written (Koheleth 7:29): "G-d made man just and they sought out many [devious] accountings." And thus is it stated in Tanchuma, Parshath Bereshith 7: "G-d made man just" — The Holy One Blessed be He, who is called "tzaddik and yashar [just]," created man in His image only to be tzaddik and yashar, as He is. And if you ask: "Why, then, did He create an evil inclination, of which it is written (Bereshith 8:21): 'For the inclination of a man's heart is evil from his youth'? You say: 'It is evil. Who can make it good?' The Holy One Blessed be He answers: "You made it evil. You were a child and did not sin. You grew up and you sinned. [That is, a man draws it (the yetzer) upon himself by his acts and by his affairs. For the Holy One Blessed be He gave man the power to withstand it and to make it his servant in many areas for the ultimate end, as it is written (Bereshith 4:17): "And you shall overcome it." And it is written (Mishlei 29:21): "One who indulges his servant from youth, etc." The words lend themselves to much elaboration.] And how many things there are in this world tougher than the yetzer hara and more bitter than it, yet you 'sweeten' them. There is nothing more bitter than lupine, yet you exert yourself to soak it and to season it in water seven times until it is sweet, and so with mustard and caper. Now, if the bitter things which I have created, you season to your needs, the yetzer hara, which is given into your hands, how much more so!"