Jephthah's daughter was the only child of the judge Jephthah. She was sacrificed as a result of her father's rash vow to God after his victory over the Ammonites. Her story is a tragic example of the consequences of unwise vows and her own acceptance of her father's oath.
Before the battle against the Ammonites, Jephthah made a vow to sacrifice whatever came out of his house first if he won. This vow would have tragic consequences.
31then whoever comes out of the doors of my house to meet me when I return safely from the Ammonites shall belong to the LORD, and I will offer him up as a burnt offering.
After the victory over the Ammonites, Jephthah's daughter came out to meet him with tambourines and dancing. She was his only child, and Jephthah was devastated by his vow.
34When Jephthah came home to Mizpah, there was his daughter, coming out to meet him with tambourines and dancing. She was his only child; he had no other son or daughter.
35When he saw her, he tore his clothes and cried, "Oh, my daughter! You have brought me to my knees; you have become the cause of my ruin. I have opened my mouth to the LORD and I cannot take it back."
With remarkable courage, she accepted her father's vow and asked only for two months to wander in the mountains and mourn her virginity with her friends.
36She said to him, "My father, you have opened your mouth to the LORD. Do to me as you have vowed, now that the LORD has avenged you on your enemies, the Ammonites.
37She said to her father, "Grant me this one request: give me two months to go and wander the hills with my friends and weep, because I will never marry."
40that year after year the young women of Israel go out for four days to commemorate the daughter of Jephthah the Gileadite.[^1]
[^1]: Or "to lament for"; the Hebrew verb is rare and may mean either to recount or to mourn.