Numbers 35:25
And the congregation shall deliver the slayer out of the hand of the revenger of blood, and the congregation shall restore him to the city of his refuge, whither he was fled: and he shall abide in it unto the death of the high priest, which was anointed with the holy oil.
When the congregation has judged the slayer to be innocent of intentional murder, it is to rescue him out of the hand of the revenger of blood. It is then to restore him to the city of his refuge to which he had fled. He is to abide in that city until the death of the high priest who was anointed with the holy oil, and only then may he return to his own possessions.