Musar к Берешит 4:13

The second: "Who bears iniquity" - and behold, this is greater than the previous. As behold, a man does not do an iniquity without creating a destructive spirit (mashchit); as it is learned (Avot 4:11), "One who transgresses a single iniquity acquires a single prosecutor." And behold, this prosecutor stands in front of the Holy One, blessed be He, and says, "X made me." And no creature exists in the world except from the flow of the Holy One, blessed be He - and behold, this destructive spirit that stands in front of the Holy One, blessed be He, from what does he exist? It would be logical that the Holy One, blessed be He, would say, "I do not nourish destructive spirits - he should go to the one that made him and be sustained from him." And the destructive spirit would go down immediately and take his soul, excise him or have him punished according to his punishment - until this destructive spirit is nullified. But the Holy One, blessed be He, does not do this; but He rather bears and tolerates the iniquity - and [just] as He nourishes and sustains the whole world, [so too] does He nourish and sustain this destructive spirit until there be one of three things: Either the sinner repents and he finishes him and nullifies him with his mortifications; or that the righteous Judge nullifies him with afflictions and death; or [that the sinner] goes to Geihinom and he pays his debt there. And that is [the meaning of] that which Kain said (Genesis 4:13), "Is my iniquity too great to bear?" And the Sages, may their memory be blessed, explained it (Midrash Tanchuma, Bereshit 9), "You tolerate the whole world" - meaning nourish and sustain - "and my iniquity is [so] heavy that you cannot tolerate it" - meaning to sustain it until I repent and repair [it]. If so, behold this is a great trait of tolerance - that He nourishes and sustains an evil creature, that the sinner created, until he repents.

The differences in atonement
In the same way as the body has sicknesses and ailments, so too does the soul. And the ailments of the soul and its diseases are its evil traits and its sins. But when an evildoer repents from his evil path, God, may He be blessed, heals the soul of the sinner - as it is stated (Psalms 41:5), “O Lord, have mercy on me, heal my soul, for I have sinned against You.” And it is [also] stated (Isaiah 6:10), “and repent and save itself.” And in the way that it is sometimes found with the sicknesses of the body that the sickness lightens itself from upon one, as does the length of most of the ailments, but the body is not cleansed of it without drinking a bitter drink and suffering further by afflicting his soul from [eating] all desirable food; so too is it with the soul sick from great iniquity: And even though most of the sickness is healed, and most parts of the punishment are removed after the repentance - and God, may He be blessed, has gone away from His anger - the soul will not yet be cleansed from the sickness and its sin will not be atoned until the sinner is made to suffer with afflictions, purified with pain and with bad and difficult things that happen to him. [This is] like the matter that is stated (Genesis 4:13-14), “My punishment is too great to bear! Since You have banished me this day from the soil, and I must avoid Your presence; and I shall be a fugitive and a wanderer in the earth; and it will come to pass, that whoever finds me will kill me.” However through repentance, most of his iniquity was forgiven, the main part of his punishment was removed and he was rescued from death - as it is stated (Genesis 4:15), “and the Lord put a mark on Cain, lest anyone who met him should kill him.” But the punishment of exile remained for him, as it is stated (Genesis 4:12), “and I shall be a fugitive and a wanderer in the earth.” Yet he had mentioned [his] migration with a double expression (fugitive and wanderer); whereas after the repentance, it is [only] stated (Genesis 4:16), “and he dwelt in the land of wandering.”

How great is the power of lashon hara, which is over and against three grave transgressions, as stated in Arachin 15b. And in Midrash Shocher Tov: "The school of R. Yishmael taught: 'All who speak lashon hara mount iniquity over and against three transgressions: idolatry, illicit relations, and the spilling of blood, it being written here (Psalms 12:4): 'the tongue that speaks "great" [i.e., slanderous] things'; but, in respect to idolatry (Shemoth 32:31): 'I pray you — this people has sinned a great sin'; in respect to illicit relations (Bereshith 39:9): 'And how shall I do this great evil?'; in respect to the spilling of blood (Ibid. 4:13): 'My sin is too great to bear'" — whence [("things" - plural)] it is derived that lashon hara is severer than these three sins." Another explanation: One who kills a man kills only one soul; but one who speaks lashon hara kills three: the speaker, the accepter, and the one spoken about. Whence do you derive this? From Doeg, who spoke lashon hara about Achimelech before Saul, and the three of them were killed: Saul, who accepted it; Achimelech, who was spoken about; and Doeg, who spoke it. Saul, who accepted it, viz. (I Samuel 31:6): "And Saul died, etc."; Achimelech, who was spoken about, viz. (Ibid. 22:16): "Die, shall you die, Achimelech"; and Doeg, who spoke it, who was driven out of the world [to come], viz. (Psalms 52:7): "G-d also will destroy you forever" from life in the world [to come]. And what caused this? Lashon hara.