The law requires an accidental killer to remain in the city of refuge until the high priest dies (Numbers 35:25).
Why must he stay even after it is established that the killing was accidental? Why can he safely return home after the high priest’s death?
Perhaps examining the procedure following a killing will answer. The killer flees to the city of refuge (verse 11), then is brought to trial between himself and the blood avenger (verse 24). If the killing was deliberate, he is handed to the avenger, who kills him. If accidental, the congregation returns him to the city of refuge (verse 25).
The Torah’s solution of saving the accidental killer through a city of refuge is surprising. If acquitted, why does he need protection? Why not prohibit the avenger from killing him? Ultimately this is exactly what happens when he returns to his holding after the high priest’s death: the avenger must accept the judgment and may not harm him. Nor is it clear why the Torah permits killing him if he leaves the refuge (verses 26–27). Accidental killing does not carry a death sentence; why should leaving make his blood his own responsibility and allow the avenger to kill him?
Blood vengeance was a social mechanism of great benefit during the centuries and millennia preceding the Torah. It ensured extreme caution against killing anyone, even accidentally. The Torah therefore recognizes and limits it rather than abolishing it entirely. On one hand, it recognizes the avenger’s right to avenge his relative even after accidental killing. On the other, it determines that accidental killing does not warrant death because it was not premeditated.
To reconcile these principles, the Torah permits the avenger to avenge his relative within a limited framework while protecting the accidental killer through cities of refuge.
In principle it recognizes the ancient law allowing the avenger to kill his relative’s killer even after accidental killing. In practice, however, the killer enjoys the congregation’s protection within the refuge, preventing the avenger from killing him. As long as he remains within its boundaries he is protected; outside them, that protection ends and his blood is his own responsibility.
According to Deuteronomy (17:8–13; 19:17; 21:5), justice in the land is entrusted to Levitical priests. If the high priest headed this priestly judicial system (see also II Chronicles 19:4–11), we can understand why his death permits the killer to return home without fear. Blood vengeance is time-limited rather than perpetual, and its duration is the tenure of the judicial system’s head, the high priest. In modern terms this resembles a statute of limitations for accidental killing expiring at his death.
The high priest during whose tenure the killing occurred permits the victim’s relative to avenge the death within legitimate blood vengeance for an act committed during his term and watch. With his death, the permitted period ends. Thereafter the avenger cannot avenge the blood without being considered a murderer. Killing the accidental killer would no longer count as blood vengeance, and the avenger would receive no congregational protection but face a murder trial. After the high priest dies, therefore, the accidental killer can return to his holding confident of protection: the time for blood vengeance has ended, and it is no longer legitimate.
