Read Numbers 35:12 Using Other Translations
And they shall be unto you cities for refuge from the avenger; that the manslayer die not, until he stand before the congregation in judgment.
The cities shall be for you a refuge from the avenger, that the manslayer may not die until he stands before the congregation for judgment.
These cities will be places of protection from a dead person’s relatives who want to avenge the death. The slayer must not be put to death before being tried by the community.