What are the sources about the angel Rephael?

The angel Rephael is not mentioned by name in the Bible, but he is mentioned in the Talmud (Yoma 37a and Bava Metzia 86b.) as one of the three angels who visited Abraham; the other two were Gabriel and Michael. Rephael means "G-d heals", and in fact Rephael was sent to heal Abraham, who was recovering from his circumcision. Ask a follow-up question