Judges 11:5-6 KJV
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: and they said unto Jephthah, Come, and be our captain, that we may fight with the children of Ammon.
Judges 11:9-10 KJV
And Jephthah said unto the elders of Gilead, If ye bring me home again to fight against the children of Ammon, and the LORD deliver them before me, shall I be your head? And the elders of Gilead said unto Jephthah, The LORD be witness between us, if we do not so according to thy words.