CAMBRIDGE, Mass. — A historian of early Christianity at Harvard Divinity School has identified a scrap of papyrus that she says was written in Coptic in the fourth century and contains a phrase never seen in any piece of Scripture: “Jesus said to them, ‘My wife ...’ ”

The faded papyrus fragment is smaller than a business card, with eight lines on one side, in black ink legible under a magnifying glass. Just below the line about Jesus having a wife, the papyrus includes a second provocative clause that purportedly says, “she will be able to be my disciple.”

The finding was made public in Rome on Tuesday at the International Congress of Coptic Studies by Karen L. King, a historian who has published several books about new Gospel discoveries and is the first woman to hold the nation’s oldest endowed chair, the Hollis professor of divinity.

The provenance of the papyrus fragment is a mystery, and its owner has asked to remain anonymous. Until Tuesday, Dr. King had shown the fragment to only a small circle of experts in papyrology and Coptic linguistics, who concluded that it is most likely not a forgery. But she and her collaborators say they are eager for more scholars to weigh in and perhaps upend their conclusions.