The avenger - Hebrew גאל gā'al, a term of which the original import is uncertain. The very obscurity of its etymology testifies to the antiquity of the office which it denotes. That office rested on the principle of Genesis 9:6, “whoso sheddeth man’s blood, by man shall his blood be shed.” The unwritten code of the East conceded to the nearest kinsman of a murdered man the right of avenging the blood that had been shed. Such rude justice necessarily involved grave evils. It gave no opportunity to the person charged with crime of establishing is innocence; it recognized no distinction between murder, manslaughter, and accidental homicide; it perpetuated family blood-feuds, the avenger of blood being liable to be treated in his turn as a murderer by the kinsman of the man whom he had slain. These grievances could not be removed as long as there was no central government, but they might be mitigated; and to do this was the object of the institution in the text (compare Exodus 21:13).
Among the Arab tribes, who are under the control of no central authority, the practice of blood-revenge subsists in full force to the present day.
The congregation - i. e. local court, consisting of the elders of the city Joshua 20:4.