Judges 11:5

And it was so, that when the children of Ammon made war against Israel, the elders of Gilead went to fetch Jephthah out of the land of Tob:

Cross-reference

Judges 10:9 Historical context

Judges 10:9 shows Ammonites already attacking Israel, setting the stage for the elders to seek Jephthah.

Judges 10:17 Historical context

Judges 10:17 records Ammonites encamped in Gilead, prompting the elders to summon Jephthah.

Judges 10:18 Historical context

Judges 10:18 records the offer of leadership to whoever fights Ammon—the call Jephthah answers.

Acts 7:35-39 recounts Moses rejected then sent as deliverer—a typological pattern Jephthah also embodies: the rejected leader God uses.

1 Cor 1:27-29 says God chooses the foolish/weak to shame the wise—Jephthah the despised son fits this pattern of God using the lowly.