'Avenger of Blood' in the Bible

The avenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.

Or in enmity shall smite him with his hand, that he die: he that smote him shall surely be put to death; for he is a murderer: the avenger of blood shall slay the murderer, when he meeteth him.

Then the congregation shall judge between the slayer and the avenger of blood according to these judgments:

And the congregation shall deliver the slayer out of the hand of the avenger of blood, and the congregation shall restore him to the city of his refuge, whither he had fled: and he shall abide in it to the death of the high priest, who was anointed with the holy oil.

And the avenger of blood find him without the borders of the city of his refuge, and the avenger of blood shall kill the slayer; he shall not be guilty of blood:

Lest the avenger of blood shall pursue the slayer, while his heart is hot, and overtake him, because the way is long, and slay him; whereas he was not worthy of death, inasmuch as he hated him not in time past.

Then the elders of his city shall send and bring him thence, and deliver him into the hand of the avenger of blood, that he may die.

That the slayer that killeth any person unawares and ignorantly, may flee thither: and they shall be your refuge from the avenger of blood.

And if the avenger of blood shall pursue him, then they shall not deliver the slayer into his hand; because he smote his neighbor ignorantly, and had not hated him before.

These were the cities appointed for all the children of Israel, and for the stranger sojourning among them, that whoever should kill any person unawares might flee thither, and not die by the hand of the avenger of blood, until he stood before the congregation.