For eighteen years, the Israelites have lived under the rule of the Ammonites.

ACT I

Zebul proposes that, faced with the loss of their religious and national identity, the Israelites must rebel. He advises that his warrior half-brother Jephtha be released from exile so that he may lead them to freedom. The Israelites vow to stop their sacrifices to the Ammonite gods and pledge themselves to Jehovah only.

Jephtha agrees to lead the Israelites into battle, on condition that he will rule as their leader should they emerge victorious. Storgè supports her husband’s mission, but will miss him in his absence. The couple’s only daughter, Iphis, is proposed to by her sweetheart Hamor; she agrees to the union – if he is willing to prove himself in battle while fighting under her father’s command. Hamor agrees, and the couple look to a happy future together in their liberated nation.

Jephtha vows to Jehovah that if he is granted victory, he shall either sacrifice to God the first living thing he sees when he gets home, or dedicate them to live eternally for God. Unaware of her husband’s vow, Storgè experiences feelings of foreboding and terror. She dreams of a great danger to Iphis, but her daughter dismisses the nightmares and comforts her mother.

When the Ammonites reject the Israelites’ peace terms, Jephtha orders them ready for battle. Together, they voice their belief that God will aid them in their struggle.

INTERVAL

ACT II

Iphis is greeted by her fiancé Hamor with the news that her father has triumphed over the Ammonites, seemingly with angelic assistance. Zebul praises Jephtha for achieving liberty for his people, but Jephtha declares the victory belongs to God.

Returning home, Jephtha is met by his daughter. He is horrified, as Iphis is the first living thing he sees. Remembering only half of his original vow and convinced he must sacrifice his daughter, he sends her away, lamenting that he would rather give his own life. Explaining the vow he has made to Zebul, Storgè and Hamor, Jephtha is met with their abject horror. In spite of their pleas, Jephtha maintains he has no choice.

Having heard of the vow, Iphis returns to her father, accepting that she must die by his hand. In anguish, Jephtha agrees. The Israelites remark on the mysteries of God’s will.

ACT III

Tormented, Jephtha prepares to make the sacrifice, praying that his daughter will be greeted into heaven after her death. Iphis accepts her fate, and the ritual of sacrifice begins – only to be interrupted at the last minute when Angel appears, declaring that Jephtha has remembered only half of his vow, and that a human sacrifice will not please God. Iphis will live, but must be dedicated to the service of the Lord, and remain a virgin. The Israelites praise God’s great mercy; Jephtha’s family are relieved. Hamor mourns that he can no longer take Iphis as his wife. The assembled Israelites celebrate God’s mercy.