"APOCRYPHAL WRITINGS ON JESUS, IN ARABIC" is the subject of a Zenit article. Excerpts, with my comments interspersed:

CORDOBA, Spain, NOV. 12, 2003 (Zenit.org).- Among the texts the early Church had to decide on were apocryphal writings in Arabic.

In this interview, Juan Pedro Monferrer, professor of Arabic language and literature at the University of Cordoba, explains what apocryphal Arabic writings are and why they are not part of the canonical writings accepted by the Church.

[...]

Q: What are the Christian apocrypha?

Monferrer: The word "apocryphal" comes from the Greek "apocryphos," which means "hidden," "secret." The term identifies a vast gamut of writings of Jewish and Christian origin that, with but a few exceptions -- as is the case of the Book of Enoch in the Coptic Church -- did not become part of the canon of the sacred books of the Bible.

The book of 1 Enoch is accepted in the Ethiopic canon but not, to my knowledge, in the Coptic canon (although Coptic fragments of it do exist).

These works, composed in the manner of biblical books, are usually classified by critics as "Apocrypha of the Old Testament" and "Apocrypha of the New Testament."

The Old Testament Apocrypha are canonical in the Catholic and Orthodox traditions but not to Jews or Protestants. Old Testament Pseudepigrapha are Bible-like books that aren't accepted in any of these major canons.

Q: Do they exist also in Arabic?

Monferrer: Not just in Arabic. The languages in which these books have come to us are very varied: Hebrew, Aramaic, Greek, Latin, Syriac, Georgian, Armenian, Coptic, etc. And also in Arabic, which has been the language of Christians of the Middle East since the sixth century, when Islam occupied the territories formerly belonging to Christian communities that lived under the Byzantine and Sassanid Persian empires.

I think he means the seventh century.

Q: What aspects of Jesus Christ underlie these writings?

Monferrer: The fundamental element contributed by the "apocrypha of the New Testament" is the information they give which does not appear in the New Testament.

All that area of which we know nothing, or perhaps very little from the Gospels -- for example, the birth of Jesus, the journey and sojourn of the Holy Family in Egypt; the 18 "hidden" years of Jesus, that is, from 12 to 30, prior to his public life -- is the material developed by the apocrypha, with the intention of making available to the Christian communities all that information they wanted on Jesus.

I think he should make it clearer that the Christian apocrypha, with the possible exception of the Nag Hammadi Gospel of Thomas, give us no new information on the historical Jesus. They have lots of legends about the childhood of Jesus and the "hidden" eighteen years, but no reliable historical data.