Tobias went out to look for a man, and he found the angel Raphael, though he did not know that he was an angel of God. [...] The young man set out with the angel, and the dog followed them. They walked on, and when night came, they camped beside the Tigris River. The young man went down to the river to wash his feet, when suddenly a large fish jumped out of the water and almost bit his foot off. Tobias cried out in fear, but the angel said to him: “Catch it and don’t let it escape.” The young man seized the fish and pulled it onto the land. Then the angel said: “Cut it open and take out the gall, the heart, and the liver, and keep them.” So the young man cut the fish open and removed the gall, the heart, and the liver. Then they cooked part of the fish and ate it. They continued their journey until they came near Media. Then Tobias asked the angel: “Brother Azariah, what are the medicinal uses of the heart, liver, and gall of the fish?” He answered: “If you burn the heart and the liver in the presence of a man or woman afflicted by a demon or evil spirit, the affliction will flee and never return. As for the gall, use it to anoint the eyes with white spots, and they will be healed.” (Tobit 5,4; 6,2–9)

The Catholic Bible contains eight books written in Greek, known as the Deuterocanonical books, which were recognized as inspired during the Council of Trent but are considered apocryphal by Jews and Protestants. These texts serve as a link between the practices and doctrinal issues of the Old and New Testaments. The book of Tobit is one of them.

This text tells the story of a pious Jew from Nineveh named Tobit, who becomes blind. Later, he sends his son Tobiah to recover some money that is in the hands of an acquaintance in the city of Media. To this end, Tobit hires a mysterious man as a guide, who turns out to be the Archangel Raphael. Raphael instructs Tobiah on how the insides of a fish will cure his father's blindness and allow him to marry his fiancée, Sarah, without any obstacles. This scene condenses several chapters of the book into one narrative.