18 Then he said to Zebah and Zalmunna, "What about the men whom you killed at Tabor?" They answered, "As you are, so were they, every one of them; they resembled the sons of a king." 19 And he replied, "They were my brothers, the sons of my mother; as the Lord lives, if you had saved them alive, I would not kill you." 20 So he said to Jether his firstborn, "Go kill them!" But the boy did not draw his sword, for he was afraid, because he was still a boy. 21 Then Zebah and Zalmunna said, "You come and kill us; for as the man is, so is his strength." So Gideon proceeded to kill Zebah and Zalmunna; and he took the crescents that were on the necks of their camels.
Matthew Henry's Commentary on Judges 8:18-21
Commentary on Judges 8:18-21
(Read Judges 8:18-21)
The kings of Midian must be reckoned with. As they confessed themselves guilty of murder, Gideon acted as the avenger of blood, being the next of kin to the persons slain. Little did they think to have heard of this so long after; but murder seldom goes unpunished in this life. Sins long forgotten by man, must be accounted for to God. What poor consolation in death from the hope of suffering less pain, and of dying with less disgrace than some others! yet many are more anxious on these accounts, than concerning the future judgment, and what will follow.