Numbers 35:33

These words are added as a reason not of the last law, Numbers 35:32, for in that case the land was cleansed without the blood of the man-slayer. but of the law next foregoing that, Numbers 35:31, in which case it holds; and the sense is, If you shall spare the murderer, or take any satisfaction for him, you do together with yourselves involve your land and people in guilt, and will certainly bring down God's vengeance upon yourselves and them.