Judges 10:9
Moreover the children of Ammon passed over Jordan to fight also against Judah, and against Benjamin, and against the house of Ephraim; so that Israel was sore distressed. Moreover the children of Ammon passed over Jordan to fight also against Judah, and against Benjamin, and against the house of Ephraim; so that Israel was sore distressed.
The Ammonites crossed the Jordan westward to make war not only on the eastern tribes but on Judah and Benjamin and the house of Ephraim. That widening of the attack brought the war into the heart of the land west of the river. The invasion pressed the people hard and left Israel severely distressed.
This Ammonite oppression continued for eighteen years. When Israel at last put away its foreign gods and returned to serving the Lord, God heard their prayers for help. He raised up Jephthah as deliverer in answer to that repentance. Jephthah defeated the Ammonites and broke their power over Israel. Yet Israel soon forgot the lesson its suffering had been meant to teach.