What does Judges 8:1 mean?

Empowered by God, Gideon (Judges 6:11) and the Israelites (Judges 7:15) routed the Midianites occupying the land (Judges 6:1–6). They had then chased them down, intent on wiping them out before they escaped across the Jordan River to the east and disappeared into the wilderness.

Unable to catch the fleeing Midianites from behind, Gideon sent messengers. They were to recruit people of Ephraim to cut off the fleeing enemy at the fords of the Jordan. The Ephraimites were successful—though some Midianites continued to escape—and brought the heads of two of the princes of Midian to Gideon (Judges 7:23–25).

Instead of celebrating their part in this great victory with Gideon, the men of Ephraim are upset. They immediately confront Gideon about not calling them to participate in the initial battle against Midian. They know that men of Naphtali, Asher, and Manasseh were summoned right away. The Ephraimites feel insulted by Gideon's snub.

Commentators suggest the Ephraimites may have believed Gideon was trying to keep the spoils of the battle away from them. Or, that they were being excluded from any lands that might be awarded after the battle. It's also possible they simply wanted to be part of any fight to vanquish the enemy that had dominated Israel for so long.