Numbers 35:22-25

22“But if he pushed him suddenly without enmity, or hurled anything on him without lying in wait 23or used a stone that could cause death, and without seeing him dropped it on him, so that he died, though he was not his enemy and did not seek his harm, 24then the congregation shall judge between the manslayer and the avenger of blood, in accordance with these rules. 25And the congregation shall rescue the manslayer from the hand of the avenger of blood, and the congregation shall restore him to his city of refuge to which he had fled, and he shall live in it until the death of the high priest who was anointed with the holy oil.