"I am Raphael, one of the seven holy angels who present the prayers of the saints and enter into the presence of the glory of the Holy One." They were both alarmed; and they fell upon their faces, for they were afraid. But he said to them, "Do not be afraid; you will be safe. But praise God for ever."
Tobit is a "entertaining angels unaware" story. Raphael is sent from heaven in response to Tobit's prayer for help and in response to a woman's plea for deliverance from a demon. He comes under an assumed name and, as is the custom with angels in such stories, engineers things toward a happy ending with wedding bells and lots of mushiness (not unlike "It's a Wonderful Life"). Tobit discovers, at the end of the story, that God was with him while he was doing all his good deeds and that everything was ordered to his good (even his sufferings). It's a fairytale-like foreshadowing of another Visitor who was not recognized when he came. Only in that story, it was he who did the suffering and entered into the Happiest of all Happy Endings. Raphael worked for him.