The enduring question of why the wicked prosper while the innocent suffer is ultimately answered by God's active providence. Divine justice guarantees that the realities of the world will eventually be balanced. The ongoing existence of evil and the suffering of the poor stand in direct contradiction to the Creator's perfect nature. Because of this, divine justice must eventually step in to eliminate wickedness and give the vulnerable exactly what they deserve.
God's promise to end the life of the wicked operates on several levels. Practically, the years of a wicked person will be cut short; they will be removed from this world and denied resurrection in the future [אבן עזרא, אלשיך]. No matter how much pride the wicked display, God's power is far greater, and He will inevitably subdue them [רמב"ן]. From a philosophical standpoint, this outcome is a fundamental necessity. Since God is the absolute source of all good, it is impossible for evil to draw lasting life and existence from Him [מלבי"ם]. Additionally, the severe punishment of the wicked is a direct response to their treatment of the weak. God judges them strictly specifically because they harmed the vulnerable [ביאור שטיינזלץ]. When God finally steps in to provide for the humble, He will completely separate the wicked from them, ensuring the corrupt can no longer live among the poor [מצודת דוד].
Alongside the removal of evil, God ensures the complete restoration of the poor. True justice in this context is not merely a legal ruling, but the active provision of whatever is proper and needed [מצודת ציון]. God will fully replenish everything that the wicked stole from the oppressed. This compensation may even be taken directly from the wealth of the wicked themselves [אלשיך]. God's deep care for the poor is rooted in the fact that He never despises or rejects their humility [רמב"ן]. Furthermore, because God is entirely perfect, ignoring the distress of the poor would be a profound injustice. Such a failure is completely impossible under His perfect rule [מלבי"ם].