The penultimate chapter in Numbers describes the cities of refuge where accidental killers can flee for safety from family retribution. There they must live out their lives, unless the high priest dies first, in which case they can return to their normal lives. What is the significance of the high priest’s death in releasing the restriction?
Rashbam suggests that the high priest is equivalent at the time to the chief judge.
Numbers 35:32 UNTIL THE DEATH OF THE PRIEST: I.e. the high priest. Following the plain meaning of Scripture, this means [that the murderer must stay in the “city of refuge”] until the chief judge dies. This is like [the idea of] (Isaiah 14:17), “who never released his prisoners to their homes.” (Translation Martin Lockshin)
The verse from Isaiah contextually describes a vision of the fallen king of Babylon:
You shall be brought down to the nether-world…those who saw you will stare; they peer at you closely. “Is this the man who shook the earth, who made realms tremble…who never released his prisoners to their homes?!” (Isaiah 14:15-17)
Rashbam uses the verse to suggest that the image of a strong ruler is maintained in part by keeping prisoners in prison. At the death of the ruler, prisoners go free. This idea echoes today in presidential pardons, especially as a president prepares to leave office.
In ancient Israelite society, the high priest is the symbol of order both societal and metaphysical. The death of the high priest thus presents a rare opportunity for those in one situation to move into another situation.
For more about Rashbam, see my introduction.