Numbers 35:31-33

Young's Literal Translation

³¹ `And ye take no atonement for the life of a murderer who [is] condemned -- to die, for he is certainly put to death;

³² and ye take no atonement for him to flee unto the city of his refuge, to turn back to dwell in the land, until the death of the priest.

³³ `And ye profane not the land which ye [are] in, for blood profaneth the land; as to the land, it is not pardoned for blood which is shed in it except by the blood of him who sheddeth it;