'Avenger of Blood' in the Bible

The blood avenger shall himself put the murderer to death; he shall put him to death when he meets him.

or if, in enmity, he struck the victim down with his hand, and he died, the one that struck the victim shall certainly be put to death; he is a murderer. The blood avenger shall put the murderer to death when he meets him.

then the congregation shall judge between the offender and the blood avenger according to these ordinances.

The congregation shall rescue the offender from the hand of the blood avenger and return him to his city of refuge, [the place] to which he had escaped; and he shall live there until the death of the high priest who was anointed with the sacred oil.

and the blood avenger finds him outside the border of his city of refuge and kills the offender, the blood avenger will not be guilty of murder,