'Avenger' in the Bible

Now if the closely related avenger pursues him, then they are not to hand the killer over to him, because he killed his neighbor without premeditation and without hating him beforehand.

These were appointed to be cities for all the Israelis and for the foreigner who lives among them, so that whoever kills anyone unintentionally may run there and not die at the hands of a closely related avenger until he stands for trial before the community.