Do not pollute the land where you are

Numbers 35:9-34
Person is a murderer the murderer is to be put to death. The anger of blood shall put the murderer to death when the meet.
They will be places of refuge from the avenger, so that anyone accused of murder may not die before they stand trial before the assembly.
This is to have the force of law for you throughout the generations to come, wherever you live. Anyone who kills a person is to be put to death as a murderer only on the testimony of witnesses. But no one is to be put to death on the testimony of only one witness.
Do not accept a ransom for the life of a murderer, who deserves to die. They are to be put to death.
Do not pollute the land where you are. Bloodshed pollutes the land, and atonement cannot be made for the land on which blood has been shed.
Why?
The Lord care about the judgment and righteous on the world.
The murder is to be put to death. And keep the land clean and holy where they are live.
God made a law to all the social event, no one can be put to death before the stand trial before the assembly, could not be put to death on the testimony of only on witness. For there are revenge or hate or some personal reason.
God is holy so we have to be live holy, without any ransom for the murderer.
How?
God is holy, so we all Christian should be walk on the right way and do the righteousness and love each other. Do not pollute the land where you are.