The spirit of the Lord came on Jephthah, who crossed Gilead and Manasseh, passed through to Mizpah in Gilead, and from Mizpah in Gilead made his way to the rear of the Ammonites. And Jephthah made a vow to the Lord, ‘If you deliver the Ammonites into my hands, then the first person to meet me from the door of my house when I return in triumph from fighting the Ammonites shall belong to the Lord, and I will offer him up as a holocaust. Jephthah marched against the Ammonites to attack them, and the Lord delivered them into his power. He harassed them from Aroer almost to Minnith (twenty towns) and to Abel-keramim. It was a very severe defeat, and the Ammonites were humbled before the Israelites.  

As Jephthah returned to his house at Mizpah, his daughter came out from it to meet him; she was dancing to the sound of timbrels. This was his only child; apart from her he had neither son nor daughter. When he saw her, he tore his clothes and exclaimed, ‘Oh my daughter, what sorrow you are bringing me! Must it be you, the cause of my ill-fortune! I have given a promise to the Lord, and I cannot unsay what I have said.’ She answered him, ‘My father, you have given a promise to the Lord; treat me as the vow you took binds you to, since the Lord has given you vengeance on your enemies the Ammonites.’ Then she said to her father, ‘Grant me one request. Let me be free for two months. I shall go and wander in the mountains, and with my companions bewail my virginity.’ He answered, ‘Go’, and let her depart for two months. So she went away with her companions and bewailed her virginity in the mountains. When the two months were over, she returned to her father, and he treated her as the vow that he had uttered bound him. She had never known a man.

Here I am, Lord! I come to do your will.

Happy the man who has placed
  his trust in the Lord
and has not gone over to the rebels
  who follow false gods.

Here I am, Lord! I come to do your will.

You do not ask for sacrifice and offerings,
  but an open ear.
You do not ask for holocaust and victim.
  Instead, here am I.

Here I am, Lord! I come to do your will.

In the scroll of the book it stands written
  that I should do your will.
My God, I delight in your law
  in the depth of my heart.

Here I am, Lord! I come to do your will.

Your justice I have proclaimed
  in the great assembly.
My lips I have not sealed;
  you know it, O Lord.

Here I am, Lord! I come to do your will.

Alleluia, alleluia!
Make me grasp the way of your precepts,
and I will muse on your wonders.
Alleluia!