Numbers 35:12

12The cities shall be for you a refuge from the avenger, that the manslayer may not die until he stands before the congregation for judgment.

Joshua 20:6

6And he shall remain in that city a  until he has stood before the congregation for judgment, until the death of him who is high priest at the time. Then the manslayer may return to his own town and his own home, to the town from which he fled.’”

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