Numbers 35:22-25

22‘But if he pushed the victim suddenly, not in enmity, or threw anything at him without malicious intent,

23or without seeing him hit him [accidentally] with a stone object that could kill him, and he died, and [the offender] was not his enemy nor intending to harm him,

24then the congregation shall judge between the offender and the blood avenger according to these ordinances.

25The congregation shall rescue the offender from the hand of the blood avenger and return him to his city of refuge, [the place] to which he had escaped; and he shall live there until the death of the high priest who was anointed with the sacred oil.