יואל, פרק ד׳, פסוק כ״א

At the end of days, a time of ultimate historic justice will arrive. God will settle the long-standing accounts with the nations of the world, repaying them for the suffering they inflicted upon the Israelites. This process involves a deep moral balancing, either by forgiving past sins or by exacting vengeance to clear an outstanding debt [מצודת ציון].

The primary approach among commentators highlights a clear distinction between the types of crimes committed by the nations. God may forgive and clear the nations for various general wrongs and offenses [רש״י, ביאור שטיינזלץ]. For instance, the theft of Israelite wealth, such as stolen silver and gold, will be wiped clean. This is because, in the future, the Israelites will reclaim the property of the nations as spoils, naturally settling that financial debt [רד״ק, מצודת דוד].

However, a strict line is drawn when it comes to the shedding of blood. The murder of the people of Judah, particularly those who were killed for the sanctification of God's name, will not be forgiven or overlooked [ביאור שטיינזלץ]. For the crime of murder, there can be no simple atonement, and no monetary ransom will ever be accepted. This severe debt can only be cleared through exact justice, requiring a life for a life. The punishment will fall either directly upon the murderers themselves or upon their descendants [רד״ק, מצודת דוד].

Another perspective focuses on the sheer number of nations that will face judgment. God carries a profound duty to avenge the spilled blood of the Israelites. While certain nations will face their punishment during the war of Gog and Magog, there are other nations guilty of shedding blood who have not yet been brought to justice. Ultimately, God promises to settle the blood debt of these remaining, unjudged nations as well [מלבי״ם].

All of these promises will reach their fulfillment during the days of the Messiah, when the Divine Presence returns to dwell in Zion forever, mirroring the eternal presence of the people of Judah [רד״ק]. God's constant presence in Zion represents more than just absolute kingship and the execution of perfect justice [רש״י, ביאור שטיינזלץ]. It also serves as a guarantee of complete protection. As the guilty nations realize their doom, the Israelites will not need to fear a desperate, final wave of violence. God will dwell directly among His people, guarding them completely from any last attempts at harm [מצודת דוד].