Exile and works of mercy
According to the Book of Tobit, Tobit belonged to the tribe of Naphtali and was carried away from his homeland to Nineveh by the Assyrians. He had observed the Law and brought offerings to the Temple in Jerusalem before the deportation, and he married a woman named Anna, by whom he had a son, Tobias.
In captivity Tobit distinguished himself by charity. He shared food and clothing with fellow exiles and gave alms, and he took particular care to bury Israelites who had been killed, even at personal risk. The Catholic Encyclopedia describes his fidelity as shown by his acts of mercy to fellow captives, and especially to the dead.
Blindness, prayer, and the journey of Tobias
The narrative relates that Tobit became blind: while he slept, droppings from sparrows fell into his eyes, and he was afterward left fully without sight. Reduced to dependence and poverty, and after reproach from his wife Anna, he prayed to God in his distress. At the same time, far off in Ecbatana, his kinswoman Sarah was afflicted by the demon Asmodeus, who had slain a succession of her suitors, and she too prayed for relief.
The book recounts that God sent the archangel Raphael, who in human guise accompanied the younger Tobias on a journey to recover ten talents of silver his father had deposited at Rhages (Rages) in Media. On the way Tobias caught a great fish in the Tigris, and Raphael directed him to keep its heart, liver, and gall. At Ecbatana the burning of the fish's offal drove off the demon, and Tobias was married to Sarah.
Healing and the book's place in Orthodox tradition
On the return to Nineveh, the gall of the fish was applied to Tobit's eyes and his sight was restored, after which Raphael revealed himself to be an angel of God before departing. Tobit then blessed God, who had chastened his people through exile but who would yet show them mercy.
The Book of Tobit is dated to roughly the third or early second century BC and is received as deuterocanonical (among the Anagignoskomena) by the Orthodox and other ancient churches, while it is absent from the Jewish Masoretic canon. As one of the Old Testament righteous, Tobit is honored by the Church together with the Forefathers of Christ during the season preparing for the Nativity.