'Avengers' in the Bible

so that anyone who kills a person unintentionally and without premeditation may run there and be protected from closely related avengers.

Then she said, "Your majesty, please remember the LORD your God, so that blood avengers don't do any more damage! Otherwise, they'll destroy my son!" So he promised, "As the LORD lives, not even a single hair from your son's head will fall to the ground!"