James Charlesworth writes (The Pseudepigrapha and Modern Research, pp. 182-184):
This pseudepigraphon is extant only in an unbound fifteenth-century Syriac manuscript in the John Rylands University Library of Manchester (Syriac MS 44, ff. 81b-83b). It was edited and translated into English by A. Mingana (Some Early Judaeo-Christian Documents in the John Rylands Library: Syriac Texts. Manchester: University of Manchester, 1917. Pp. 52-59 [text], 24-29 [transl.]; repr. from BJRL 4  59-118).
Only Mingana has published research on this composition. He suggested that the original text could have been written in the Roman period, perhaps after the ravaging of Palestine by Vespasian or Hadrian, because of the mention of emigration from Palestine. The provenance, according to him, is probably Egyptian or Palestinian.
In favor of an early date is the internal evidence. The Roman king will move about (chp. 1). The Romans will defeat the [Persians] in a severe war (chp. 2). The Romans will find it difficult to subdue the pirates (lestane, Gk. loan word) from Palestine.
External data tend to resist the assumption of an early date. The work is not cited by the Fathers, the genre (see below) is typical of later writings (cf. G. Furlani, "Astrologisches aus syrischen Handschriften," ZDMG 75  122-28; A. Baumstark, Geschicte, pp. 230, 352f.; G. Graf, Geschichte, p. 216), and brontologia, selenodromia, and calendologia are listed by Nicephorus with later writings such as the Apocalypse of Ezra and the Apocalypse of Zosimus (cf. M. R. James' comments in R. L. Bensly's The Fourth Book of Ezra [T&S 3.2] Cambridge: CUP, 1895; pp. xxivf.).
Generally speaking internal evidence takes precedence over external; moreover, the latter in this case is not impressive. First, numerous early works, such as the Odes of Solomon, are not quoted by the Fathers; others, such as Jubilees, are not mentioned in the famous lists of apocryphal works. Second, medieval kalandologia could be modeled upon earlier examples: Jewish horoscopes and astrological documents are not always late, since examples of them have been found at Qumran (4QCryptic; cf. J. M. Allegro, no. 129; 4Q186, cf. J. Carmignac, "Les horoscopes de Qumran," RQ 5  199-217). Jewish interest in the Zodiac is clearly much earlier than we once envisioned (cf. SibOr 5:512-31). Third, Nicephorus' order of listing works is of no consequence, since there is no evidence that he followed a chronological order; moreover, the Apocalypse of Zosimus appears to contain early traditions (see the entry below).
Indicative of an Egyptian, perhaps Alexandrian, provenance is the mention of the Nile (chps. 1, 2, 3, 4, 5, , 7, 8, 12), Egypt (chps. 1, 2, 7, 8, 9, 12), and Alexandria (chps. 4, 6). The numerous realia are typical of Egypt, but there is no mention of beer or crocodiles. Probably reflecting an Egyptian provenance, since only Egypt and Palestine (chps. , 11, 12) are likely, is the note of pirates who come "from Palestine." The original language is Semitic, with Greek loan words, since there are abundant Semitisms and personal names are defined in terms of the Semitic alphabet (chps. 2, 6, 7, 8, 9, 10, 11, 12). Future research might indicate that the Treatise of Shem was composed by one of the Therapeutae. It will be interesting to see if there is any relation between the Treatise of Shem and the unpublished Nag Hammadi Codex entitled the Paraphrase of Shem cf. J. M. Robinson, no. 541, esp. pp. 378-80).
The work is a Jewish calendologion, of which other examples are attributed to Ezra (cf. James, LAOT, pp. 80f.), describing the features of a year when it begins in a particular sign of the Zodiac. The composition can be divided into twelve chapters, following the twelve signs running counter-clockwise from Aries to Capricorn, but reversing the order of the last two so that Pisces preceds Aquarius. The worst year apparently begins in Aries, the first, and the best in Pisces (the eschatological peace and harmony noted at the end prompts the question whether this section was copied inadvertantly, due to parablepsis and the confusion between rubrics, before the one which is now last).
James Charlesworth writes: "It is significant that the Treatise of Shem was composed about the time that the vernal equinox (the traditional beginning of the year, the start of spring) moved from Aries to Pisces, where it has been ever since, although it is about to move into Aquarius. This change, G. de Santillana has argued, would have evoked strong 'astrological emotion' since one age was succeeding another. It is certainly not clear, however, that this phenomenon was perceived or comprehended in antiquity. If it was, then the Treatise of Shem would be an unparalleled record of this monumental shift, the Precession of the Equinoxes." (The Old Testament Pseudepigraph, vol. 1, p. 480)
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