At first glance, one might wonder what the problem is here. Jephthah subdued a common enemy! Shouldn't the men of Ephraim be thrilled? One would think so, but obviously a deep spirit of jealousy is at work here, as had been manifested previously (e.g., 8:1). These men of Ephraim were immature and didn't like others to be successful. They have an attitude problem and they lash out at Jephthah for no good reason. Jephthah had invited them to help but they refused, and now they are angry at him being successful without their assistance and they want to kill him! Ridiculous!
"Now Jephthah gathered together all the men of Gilead and fought against Ephraim. And the men of Gilead defeated Ephraim, because they said, 'You Gileadites are fugitives of Ephraim among the Ephraimites and among the Manassites.' The Gileadites seized the fords of the Jordan before the Ephraimites arrived. And when any Ephraimite who escaped said, 'Let me cross over,' the men of Gilead would say to him, 'Are you an Ephraimite?' If he said, 'No,' then they would say to him, 'Then say, "Shibboleth"!' And he would say, 'Sibboleth,' for he could not pronounce it right. Then they would take him and kill him at the fords of the Jordan. There fell at that time forty-two thousand Ephraimites. And Jephthah judged Israel six years. Then Jephthah the Gileadite died and was buried in among the cities of Gilead" (12:4-7).
The Ephraimites chose to fight against the men of Gilead for no good reason, and God blessed the Gileadites with victory. Over 40,000 Ephraimites died needlessly because of pride and stupidity! The Ephraimites who escaped from the battle would desire to cross the Jordan River to flee. However, the Gileadites took control of the fords and killed any Ephraimite who tried to cross. Even if an Ephraimite lied about his identity, the Gileadites would have him pronounce a word ("Shibboleth") and his diction would betray him. In America, it is generally easy to tell from what part of the country someone has lived most recently because of his accent. So it was in Israel (e.g., Matt. 26:73). Apparently the Ephraimites had difficulty pronouncing the "sh" sound and the Gileadites knew this and used it against them for identification purposes. Jephthah was no fool; he tested those who claimed to be friends and would ascertain whether they were truly foes (cf. I John 4:1). Jephthah's time as a deliverer (or judge) was short-lived (only six years), but he made an impact, endowing the next generation with peace.
"After him, Ibzan of Bethlehem judged Israel. He had thirty sons. And he gave away thirty daughters in marriage, and brought in thirty daughters from elsewhere for his sons. He judged Israel seven years. Then Ibzan died and was buried at Bethlehem [this is probably Bethlehem in Zebulun, not the same place Christ was born - SRB]. After him, Elon the Zebulunite judged Israel. He judged Israel ten years. And Elon the Zebulunite died and was buried at Aijalon in the country of Zebulun. After him, Abdon the son of Hillel the Pirathonite judged Israel. He had forty sons and thirty grandsons, who rode on seventy young donkeys. He judged Israel eight years. Then Abdon the son of Hillel the Pirathonite died and was buried in Pirathon in the land of Ephraim, in the mountains of the Amalekites" (12:8-15).
It is interesting that no significant events are recorded during the reign of these three judges. In one sense that is good, for it implies peace. However, we learn in the next chapter that the peace is short lived because Israel does not remain faithful to the LORD! It doesn't take long for a nation to corrupt itself and leave behind the way of righteousness! Also, we have a record here of more extremely large families with dozens of children. Such was made possible by one man marrying a multiplicity of women. Polygamy, though not a part of God's ideal will for marriage, was widely practiced throughout the nation's history and caused many problems, as the Scriptures illustrate elsewhere (e.g., II Sam. 13ff; I Kings 11). The people seemed to live in peace and prosperity during this time, but it will not last because of their sins!
Thank you for listening, and may the Lord bless you as you strive to do His will.