JOS 20:9

9 Any Israeli or any foreigner who lived among us, anyone who killed someone ◄accidentally/without planning to do it►, was allowed to run to one of those cities, and be safe/protected from some relative of the person who died coming there and killing him to get revenge. He could stay in that city until there was a trial there [to decide whether he was telling the truth or not when he said that he did not plan to kill that person].