Musar do Izajasza 6:7

Thus when the penitent man recognizes his sin and admits it, and reflects on his evil, repents of it and completely regrets ever having done it, as he would regret [in annulling] a certain vow, in which case there is complete regret, and he desires and longs that this deed had never been committed, and pains himself strongly that the matter was done, and renounces it for the future, and flees from it - then the uprooting of the deed from his will is counted to him as the annulment of a vow and he gains atonement for it. As scripture says: "your iniquity is gone and your sin atoned for" (Isaiah 6:7) - that the sin is actually removed from existence, and uprooted through his paining himself and regretting in the present what he had done in the past.

The second detrimental factor, laughter and levity, is very severe. For one who is immersed in these is like one immersed in the great sea, from which it is extremely difficult to escape. For behold, laughter destroys a man's heart until reason and knowledge no longer rule in him. He becomes like a drunkard or a madman whereby it is impossible to give counsel or guide them for they are incapable of accepting any direction.

Behold, the prophet Isaiah would "scream like a crane" for he saw that this was what left no room for his rebukes to make an impression thus ruining all hope for the sinners. This is what he said: "And now do not be mockers lest your afflictions be strengthened" (Isaiah 28:22).