And the elders of Gilead said to Jephthah, "The LORD will be a witness between us, if we do not do according to your words."
Judges 11:10
Surrounding context
11:9 So Jephthah said to the elders of Gilead, "If you take me back home to fight against the people of Ammon, and the LORD delivers them to me, shall I be your head?"
11:10 And the elders of Gilead said to Jephthah, "The LORD will be a witness between us, if we do not do according to your words."
11:11 Then Jephthah went with the elders of Gilead, and the people made him head and commander over them; and Jephthah spoke all his words before the LORD in Mizpah.