Joshua 20:3

20:3 that the manslayer who kills any person unwittingly [and] unawares may flee there: and they shall be to you for a refuge from the avenger of blood.
-World English Bible

Other Translation

20:3 That the slayer that killeth [any] person unawares [and] unwittingly may flee thither: and they shall be your refuge from the avenger of blood.
-King James Version