Then said he unto Zebah and Zalmunna— The history is so extremely short in this place, that we can only form conjectures: it is plain, from the examination of these princes, that they had slain Gideon's brethren; but with what circumstances we know not. They tell Gideon, that they resembled him; as thou art; so were they; i.e. men in whose aspect greatness and majesty were conspicuous; every one resembled the children of a king. For this murder of his brethren, Gideon orders his eldest son Jether, Joshua 8:20 to rise up and slay Zeba and Zalmunna; for it was not unusual in ancient times for great persons to execute those offenders upon whom they passed sentence. They had then no public executioners. Samuel himself hewed Agag to pieces in Gilgal; and Benaiah, the general of the army, fell upon Joab at the horns of the altar. Gideon, like another Asdrubal, would have animated his son by this execution to a zeal against the enemies of Israel; but the youth was afraid to obey his father's commands; terrified, possibly, by the fierce countenance of the Midianites, intrepid at the view of death, as their next words prove; in which they entreat Gideon, as a man of strength and dignity, to dispatch them, that they might not have the disgrace of their defeat augmented by an ignominious death from the hands of a stripling.
Note; The day is coming when every secret thing will be brought to light, and such conviction flash on the offenders, that they shall no longer be able to conceal their guilt.