Out of the mouth of babies and infants, you have established strength because of your foes, to still the enemy and the avenger. (Psalm 8:2 ESV)
Who is the avenger?
Before Israel entered the Promised Land, God told them to set apart three cities, and then later three more cities, as places of refuge. If someone unintentionally killed a person, they could flee to a city of refuge and not be killed by the kinsman redeemer, or the person related to the dead person with the legal authority to seek recompense. “You shall select cities to be cities of refuge for you, that the manslayer who kills any person without intent may flee there. The cities shall be for you a refuge from the avenger, that the manslayer may not die until he stands before the congregation for judgment” (Numbers 35:11-12 ESV).
The word avenger in the book of Numbers is a different word than in Psalm 8:2. In Numbers the word represents a person who is related to the deceased. If someone murders another, the murdered person’s relative has the right of revenge, to take the life of the murderer. “The avenger of blood shall himself put the murderer to death; when he meets him, he shall put him to death”(Numbers 35:19 ESV). The rules for those who kill accidentally are strict, just as the rules for the avenger are strict.
The cities of refuge were places where an innocent person, who accidentally killed another, may flee from the avenger of blood. These cities were places where an innocent person could escape and trust that they would not be killed by the avenger. These cities were not asylums where those who intentionally murdered could flee to escape punishment.
But if anyone hates his neighbor and lies in wait for him and attacks him and strikes him fatally so that he dies, and he flees into one of these cities, then the elders of his city shall send and take him from there, and hand him over to the avenger of blood, so that he may die. Your eye shall not pity him, but you shall purge the guilt of innocent blood from Israel, so that it may be well with you. (Deuteronomy 19:11-13 ESV)
In The Law of Moses, the avenger is the kinsman-redeemer given the authority to both avenge and to ransom from slavery. They have the authority and responsibility over the people and property of their family.
In Psalm 8 the word for avenger means one who metes out just sentences against those who have committed crimes against God. It is the avenger who confronts the enemies of God, His foes, with justice. Most often in Scripture the word revenge refers to God taking action against His enemies. Where there is a place for vengeance in crimes against people, such as murder, after the crime is verified by witnesses, there is no hesitation on God’s part to extract vengeance when He has been wronged.
You shall not hate your brother in your heart, but you shall reason frankly with your neighbor, lest you incur sin because of him. You shall not take vengeance or bear a grudge against the sons of your own people, but you shall love your neighbor as yourself: I am the LORD (Leviticus 19:17-18 ESV).
God alone has the absolute right to judge and avenge Himself against those who rebel against Him. He may use peoples and nations to execute His judgments but no one other than He occupies the position of judge over another. Yet, part of the sin nature is the desire to judge those who do us wrong, and to especially judge God. No created being has the right to judge the Creator. As Creator, God has the eternal right to judge those whom He has created.