Numbers 35:33
So ye shall not pollute the land wherein ye are: for blood it defileth the land: and the land cannot be cleansed of the blood that is shed therein, but by the blood of him that shed it.
So ye shall not pollute the land wherein ye are,.... The land of Canaan, as it had been by the old inhabitants of it, by idolatry, adultery, and murder:
for blood it defileth the land: the shedding of innocent blood defiles a nation, and the inhabitants of it, brings guilt thereon, and subjects to punishment:
and the land cannot be cleansed of the blood that is shed therein, but by the blood of him that shed it; or "there can be no expiation" {b}, or "atonement made" for it in any other way; the blood of the murderer is required at his hands, and nothing short of it will satisfy law and justice, see Genesis 9:6.
{b} rpky al "non posset expiatio", Junius & Tremellius, Piscator; to the same sense Pagninus, Montanus, Tigurine version.