The Penitence of Jamnes and Mambres is a lost text from the Old Testament pseudepigrapha concerning Jamnes and Mambres, the traditional names for the two sorcerers who challenged Moses when he met the pharaoh to ask for the release of the Israelites. The book is mentioned in the Decretum Gelasianum in the list of Apocryphal Books under apocryphus. The book may be identical to the Apocryphon of Jannes and Jambres. In the Decretum Gelasium it is called the Repentance of Jannes and Jambres. In the text the magicians are called Jamnes and Mambres as opposed to Jannes and Jambres.