Avenger of blood

The one responsible in OT law for carrying out the death penalty in the case of murder, usually, the murdered person's next of kin.

The responsibility of the avenger of blood

Numbers 35:16–21 See also Numbers 35:26–27; Deuteronomy 19:11–12

If, however, anyone strikes a person with an iron object and kills him, he is a murderer; the murderer must surely be put to death. Or if anyone has in his hand a stone of deadly size, and he strikes and kills another, he is a murderer; the murderer must surely be put to death. If anyone has in his hand a deadly object of wood, and he strikes and kills another, he is a murderer; the murderer must surely be put to death. The avenger of blood is to put the murderer to death; when he finds him, he is to kill him. Likewise, if anyone maliciously pushes another or intentionally throws an object at him and kills him, or if in hostility he strikes him with his hand and he dies, the one who struck him must surely be put to death; he is a murderer. When the avenger of blood finds the murderer, he is to kill him.

Protection from the avenger of blood

Numbers 35:10–15 See also Numbers 35:22–25; Deuteronomy 19:4–6; Joshua 20:1–6

“Speak to the Israelites and tell them: When you cross the Jordan into the land of Canaan, designate cities to serve as your cities of refuge, so that a person who kills someone unintentionally may flee there. You are to have these cities as a refuge from the avenger, so that the manslayer will not die until he stands trial before the assembly. The cities you select will be your six cities of refuge. Select three cities across the Jordan and three in the land of Canaan as cities of refuge. These six cities will serve as a refuge for the Israelites and for the foreigner or stranger among them, so that anyone who kills a person unintentionally may flee there.

Examples of avenging of blood

Genesis 4:24; 2 Samuel 3:27, 2 Samuel 14:11

God as an avenger of blood

Deuteronomy 32:43 See also Judges 9:23–24; 2 Kings 9:7; Psalm 9:12, Psalm 79:10; Revelation 6:10, Revelation 19:2

Rejoice, O heavens, with Him, and let all God’s angels worship Him. Rejoice, O nations, with His people; for He will avenge the blood of His children. He will take vengeance on His adversaries and repay those who hate Him; He will cleanse His land and His people.