Musar su Salmi 92:8

It is the practice of the Shechinah to afflict the righteous in this world so that they may inherit the World to Come. Conversely, the wicked are rewarded here for their few good deeds in order to deprive them of the World to Come. The “fool” does not understand “this,” that is, the ways of the Shechinah.. Therefore expresses bewilderment and doubt, Heaven forbid. He says, “See how this righteous and upright individual suffers while we evildoers enjoy tranquility, inexplicably increasing in dominion and prospering in all that we do!” But the wise man has his eyes in his head. He realizes that the inexplicable success of the wicked is merely an instance of what is described in the verse: “When the wicked bloom like grass and the evildoers blossom” (Tehillim 92:8). The verse concludes, “It is only that they may be destroyed forever,” that is, in the World to Come, the world of eternal life. For they will become ashes beneath the feet of the righteous, as it is written, “And you shall tread upon the wicked, for they shall be ashes under the soles of your feet” (Malachi 3:21).