Then the Spirit of Yahweh came on Jephthah, and he passed over Gilead and Manasseh, and passed over Mizpeh of Gilead, and from Mizpeh of Gilead he passed over to the children of Ammon.
Jephthah made a vow before going into battle. He promised that if the Lord would give him victory he would give God whatever came out of the door of his house when he returned from the conflict (Judges 11:30-31). He would offer this person or animal either as a sacrifice of dedication to the Lord or as a burnt offering of worship (Judges 11:31).