Numbers 35:33

“So ye shall not pollute the land wherein ye are, etc.] 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” f527, 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 <010906>Genesis 9:6).”

“35:33 for murder pollutes the land: If the slayer in either a homicide or involuntary manslaughter were not dealt with as commanded, God regarded the land as polluted, because human bloodshed required death (Gen 4:10-11; 9:6; contrast Exod 21:29-30; see also Lev 18:28; Ezek 36:17-18; Hos 4:2-3). In its stern warning about the evil of murder, this entire passage highlights the absolute value of human life (Exod 20:13).”

“it defileth: Lev 18:25; Deu 21:1-8, Deu 21:23; Kg2 23:26, Kg2 24:4; Psa 106:28; Isa 26:21; Eze 22:24-27; Hos 4:2, Hos 4:3; Mic 4:11; Mat 23:31-35; Luk 11:50, Luk 11:51 the land cannot be cleansed: Heb. there can be no expiation for the land Numbers 35:34”

“The Israelites were not to desecrate their land by sparing the murderer; as blood, i.e., bloodshed or murder, desecrated the land, and there was no expiation (יכפּר) to the land for the blood that was shed in it, except through the blood of the man who had shed it, i.e., through the execution of the murderer, by which justice would be satisfied. Numbers 35:34”