In quoting an apocryphal saying supposed to have been given in answer to Salome, he says, expressly: 'We do not find this saying in the four Gospels that have been handed down to us, but in that according to the Egyptians' [Endnote 317:4].
Tertullian is still more exclusive.

He not only regards the four Gospels as inspired and authoritative, but he makes no use of any extra-canonical Gospel.

The Gospels indeed held for him precisely the same position that they do with orthodox Christians now.

He says respecting the Gospels: 'In the first place we lay it down that the evangelical document (evangelicum instrumentum [Endnote 318:1]) has for its authors the Apostles, to whom this office of preaching the Gospel was committed by the Lord Himself.

If it has also Apostolic men, yet not these alone but in company with Apostles and after Apostles.