Bible Notes Online - Judges 8 - ESV
Commentary

v1-3: Ephraim complained against Gideon, because they had not been chosen to fight against Midian. Gideon's answer was simply that they had captured and killed Oreb and Zeeb, the leaders of Midian (7.25). He did not go into any discussion about who had heard the summons (6.35), or who had been sent home (7.3,7). Sometimes the best answer is short.

v4: Gideon and the three hundred crossed over the Jordan. They were exhausted after the initial battle, but zealous to complete the job, 2 Cor 4.8-9. As in Joshua and elsewhere, victory comes by the promise of God, and by real effort by the people.  Do we sometimes think that we can gain the victory without effort?

v5-9: Succoth and Peniel refused to help Gideon; a different problem to that of Ephraim. So Gideon had to face a vast Midianite army, and cope with uncooperative Israelites.

These places meant "refreshment", and "face of God", as they had been places of past blessing. But they refused to share blessing with others.

v10-12:   A further victory, with 300 against 15,000. One mighty victory against the odds can give strength and faith for another.

v13-17: Gideon returned to Succoth and Peniel, as promised. The people of God did act as such, and they suffered judgment at Gideon’s hands.

v18-21: Zebah and Zalmunna confessed to killing men like Gideon, each one like a prince; Gideon owned them as his brothers, and exercised judgment on Zebah and Zalmunna. Gideon was no longer afraid as he killed the Midianite kings.

v22: Following the mighty victory, Gideon suddenly became very popular. The people attributed the victory to him, not to the Lord God (1 Sam 5.7). Yet the leader of the people must lead them into victory.

v23: Gideon's response was correct, that the Lord God be their ruler. Sadly, his son, Abimelech, did become king over Israel (ch 9).

v25-27: Gideon probably had the best of motives in making the ephod. He wanted the people to recall the victory, and give God the glory. very quickly, it seems, the people began to worship the ephod, and it became a snare. This illustrates the normal human tendency to sin, 2 Kings 18.4.

v28: As with previous judges, the land enjoyed peace, once the oppressing enemy had been defeated.

v33: Once Gideon had died, the people fell back into idolatry. The forgot the Lord, and Gideon, the Lord's servant. No wonder the writer of Ecclesiastes wrote with sadness of people's ingratitude; Eccl 9.13-16.