“he who avenges blood.” In this context, God is the avenger of blood. In Old Testament times there was no police force; it was up to families to protect themselves, and if someone killed a member of the family, one of the family members would kill the murderer. That family member was known as “the avenger of blood.” In this verse, God assures the weak and downtrodden that the injustices they have suffered at the hands of wicked people will be avenged. Similarly, Romans 12:19 tells the Christian not to take personal revenge, for God will avenge those who are treated unrighteously.