The Lost Apocrypha of the Old Testament/Seth
Seth was in like manner the ostensible author of many Gnostic books. But there is a passage both in Syncellus and Cedrenus which deserves to be quoted as possibly preserving a notice of a lost writing under his name, of less eccentric character. I quote Cedrenus (ed. Migne, col. 8): "Seth is recorded as the third son of Adam. He married his own sister, called Asouam, and begat Enos. Seth signifies resurrection. He was also called God, because of the shining of his face, which lasted all his life. Moses also had this grace, and so veiled himself when he spoke with the Jews, for forty years. Seth gave names to the seven planets, and comprehended the lore of the movements of the heavens. He also prepared two pillars, one of stone and one of brick, and wrote these things upon them." (The rest of this familiar story from Josephus is then given.) "He also devised the Hebrew letters. Now Seth was born in the 230th year of Adam, and was weaned when he was twelve years old, and in the 270th year of Adam Seth was caught away by an angel and instructed in what concerned the future transgression of his sons (that is to say, the Watchers, who were also called Sons of God), and concerning the Flood and the coming of the Saviour. And on the fortieth day after he had disappeared, he returned and told the protoplasts all that he had been taught by the angel. He was comely and well-formed, both he and those that were born of him, who were called Watchers and Sons of God because of the shining of the face of Seth. And they dwelt on the higher land of Eden near to Paradise, living the life of angels, until the 1000th year of the world."
Dr. Charles may be right in regarding this statement (about the revelations made to Seth) as an attempt to transfer to him the wisdom and the position which properly belonged to Enoch. Still, there is evidence, at any rate, of Messianic prophecies attributed to Seth, besides those which Adam revealed to him, and which are recorded in the fragments of the Testament, and more shortly in the Life.
In particular, the Arian author of a commentary on St. Matthew, printed with the works of St. Chrysostom and known as the Opus Imperfectum, quotes a story about the Magi, "among whom (in their own country) was current a writing inscribed with the name of Seth, concerning the star which was to appear and the gifts that were to be offered to Christ." In the Armenian Gospel of the Infancy, translated into French by P. Peeters (1914), the Magi are represented as bringing with them a Messianic prophecy by Adam which Seth had received and handed on to his posterity. These are, of course. Christian compositions, and not necessarily or probably of early date.