Judges 12:4 - Joseph Benson’s Commentary on the Old and New Testaments

The men of Gilead smote Ephraim, because they said, &c. That which provoked the army of Jephthah to kill so many of them was their insulting language, added to their threats, whereby they reproached the men of Gilead, (who were the chief managers of the late war,) as if they were but the scum and dregs of the tribe of Ephraim. Ye Gileadites are fugitives of Ephraim A contemptuous expression, designed to provoke and kindle wrath. The word Ephraim is here taken largely, as comprehending the other neighbouring tribes, of which Ephraim was the chief, and especially their brethren of Manasseh, who lived next to them, and were descended from the same father, Joseph. By Gileadites, they seem here principally to mean, those Manassites who inhabited Gilead, beyond Jordan. And although other Gileadites were joined with them, yet they vent their passion principally against these, because they envied them most, as having had a chief hand in the victory. These they opprobriously call fugitives, that is, such as had deserted their brethren of Ephraim and Manasseh, planted themselves beyond Jordan, at a distance from their brethren, and were alienated in affection from them.