Judges 11:1-40

He was a mighty man of valour, he was the son of a harlot: and Gilead begat Jephthah. And Gilead's wife bore him sons; and the wife's sons when they grew up, they threw Jephthah out, and they said, You're not gonna inherit our father's house; you're the son of a strange woman. So Jephthah fled from his brothers, and he dwelled in the land of Tob: and there gathered unto him vain men who began to [sort of pal around him]. And it came to pass in the process of time, that the children of Ammon made war against Israel. And it was so, when the children of Ammon made war against Israel, the elders of Gilead sent to fetch Jephthah out of the land of Tob: And they said to Jephthah, Come, and be our captain, that we might fight with the children of Ammon. And Jephthah said unto the elders of Gilead, Did you not hate me, and expel me out of my father's house? why are you now come because you are in distress? The elders of Gilead said unto Jephthah, Therefore we turn again to thee now, that you may go with us, and fight against the children of Ammon, and be our head over all of the inhabitants of Gilead. So Jephthah said unto the elders of Gilead, If you bring me home again to fight against the children of Ammon, and the LORD delivers them before me, shall I be your head? And the elders of Gilead said to Jephthah, The LORD be witness between us, if we do not according to your words (Judges 11:1-10).

In other words will you let me rule over you?

So Jephthah went with the elders of Gilead, the people made him the head and captain over them: and Jephthah uttered all of his words before the LORD in Mizpeh. And Jephthah sent messengers unto the king of the children of Ammon, saying, What have you to do with me, that you come against me to fight in my land? And the king of the children of Ammon and said to the messengers of Jephthah, Because Israel took away my land, when they came up out of Egypt, from Arnon even to Jabbok, and unto Jordan: and now therefore restore those lands again peaceably (Judges 11:11-13).

So there was a little sort of a running feud. Jephthah sent, and he said, "Hey, why are you guys coming to fight to take away our land?" And they sent back, "Hey, we were here before you ever thought of being here. We lived here before you came and you came and took the land away from us."
So he wrote back to them another message. It said, "No way. We were willing to live peaceably. You came out against us. You started the fight and we wiped you. And so the land belongs to us. We've been dwelling there all along. How come you haven't come sooner to reclaim it? Why didn't you take it then you know, if it was your land? So we settled in it. It's our land."
And so they then gathered together to battle. Now, at this point Jephthah made a vow unto God. He said, "Lord if you will deliver these people of Ammon or the Ammonites into my hand giving me victory over them, then I will sacrifice unto you the first thing that comes out of the door of my house when I return home as a burnt offering unto thee."
So God delivered the Ammonites into the hands of Jephthah. And he was coming home victorious, leading the armies and who should come out the door of his house then his daughter, his only child? With a tambourine and a song that she had made up of the great victories of her father and the how great of dad and everything he was. And when he saw her come out the door he said, "Oh sweetheart, you've brought grief to my soul today."
And she said, "Dad, whatever you promised the Lord to do, go ahead and do." And so he told the vow that he had made and she said, "All right you know, you've made a vow to God and you're to do it but," she said, "Allow me a couple of months to go through the mountains with my friends and just sort of bewail my virginity." And so she went through the mountains bewailing her virginity for a couple of months.

And it came to pass [verse thirty-nine] at the end of two months, that she returned unto her father, who did with her according to his vow which he had vowed: and she knew no man. And it was a custom in Israel, that the daughters of Israel went yearly to lament the daughter of Jephthah the Gileadite four days in a year (Judges 11:39-40).

Now, number one, God had forbidden human sacrifice. There is a question of whether or not he actually killed her. The burnt offering sacrifice was actually a sacrifice of consecration unto God. And there are some commentators who teach that he gave her to God to perpetual virginity. In other words, to keep her from ever marrying and she was consigned to a life of celibacy because of the vow her father had made. That is possible, it isn't probable but it is possible. From the apparent reading of the text he did this awful thing and actually sacrificed his daughter unto the Lord.
However, I am convinced that God did not require it of him nor would God require it of him. Under the law where your first child actually was to be given to God, God made provisions for the redemption of the first child with an animal. And I'm certain that God would have allowed Jephthah to make a substitution for his daughter in this case.
We must remember that in the society that was surrounding the children of Israel in those days, human sacrifice of your children was a very common thing to the pagan gods. In the worship of Moloch, in the worship of Baal, the common practice was the sacrificing of your children unto god, unto your gods. In the uncovering of the houses of the Canaanites, in the foundations of the houses they discovered many jars with the skeletons of babies. They considered a good luck omen to actually bury your baby in the foundation when you build a house sacrificing it unto the gods and so forth. And it was common practice among the pagans by which the children of Israel surrounded. But it was something that was strictly forbidden by God. So if Jephthah did it, he did it of his own will, not because God demanded it. It is a very horrible thing. It is hard for us to understand. We cannot really blame God. You say, "But why did God allow her to come first out of the house? Why didn't she chase the cat out in front of her or something?" That I don't know. "