What does Judges 8:20 mean?

Gideon has made it clear that he is about to kill the two Midianite kings. This will be done, in part, for killing his brothers at Mount Tabor (Judges 8:18–19). Instead of doing it himself, he commands his young, firstborn son Jether to carry out the sentence. Gideon may have believed he was giving his son the honor of avenging his uncles. Perhaps he also meant to shame Zebah and Zalmunna by allowing a boy to end their lives.

Whatever Gideon's motive, this becomes a difficult scene to witness. Jether is terrified at the thought of killing these men. Being confronted with captives, and in front of witnesses, and without prior experience, the boy does not even draw his sword. Instead of receiving the honor of avenging his family, Jether likely experienced shame for his fear and lack of will. Gideon's demand comes across as insensitive—even cruel—through modern eyes.

As it happens, the condemned men themselves will provide Gideon's son with an escape from this awkward exchange. Since flattery has not worked, and they know they will die, they shift to challenging Gideon's own manhood (Judges 8:21).