Agrapha (ἄγραφον; Greek for "non written"; singular ágraphon) are sayings of Jesus that are not found in the canonical Gospels.
According to A. J. Maas, supposed agrapha must satisfy three conditions:[1] Mere additions to pre-existing sayings are not considered agrapha.
According to A. J. Maas,[1] for agrapha to be genuine, they must be supported by external and internal evidence.
This means that early writers, like Papias, Clement, Irenaeus, and Justin Martyr would have quoted them, and the message of the agrapha must not conflict with the teachings of Jesus contained in the canonical Gospels.
The Catholic Encyclopedia-"Agrapha" - 1907, therefore free of copyright