Joshua 20:3

that the manslayer who strikes any person without intent or unknowingly may flee there . They shall be for you a refuge from the avenger of blood .

so that anyone who kills a person accidentally and unintentionally may flee there and find protection from the avenger of blood.

That the slayer that killeth any person unawares and unwittingly may flee thither: and they shall be your refuge from the avenger of blood.