The Revelation of Metatron is a medieval Jewish work, that claims to have been written in the late-2nd century AD by Rabbi Ishmael 'the High Priest.' It is known by various names, including the Sepher Hekhalot (Book of the Palaces), the 3rd Book of Enoch, and the Book of Rabbi Ishmael the High Priest, although its most common name, is the Revelation of Metatron. The earliest name for the work was likely the Sepher Hekhalot (Book of the Palaces), however, all copies have been so reworked that it cannot be known for sure. It is clear that Rabbi Ishmael did not write it, and his name, which is in almost every verse, was inserted to replace another name that the medieval publisher did not want associated with the book. Rabbi Ishmael was the author of the book called Hekhalot Rabbati (Greater Palaces) sometime between 100 and 130 AD, and his name was late used as a pseudonym by many authors of Merkabah literature between 200 and 1000 AD.
Hekhalot (Palaces) and Merkabah (Flying-chariot) are two related forms of Jewish literature that developed from the visions from in the prophetic books, such as Ezekiel, apocalyptic books, such as Isaiah, and the Enochian tradition. Hekhalot literature, which includes books that focus on Merkabah, such as Maaseh Merkabah (Working of the Flying-Chariot), is the term used for works written during the Second Temple era. During the Second Jewish-Roman War, Merkabah literature was prohibited, largely it seems, due to the teachings of Rabbi Elisha ben Abujah, more commonly referred to as 'Aher,' meaning 'the other.' After the literature was banned, it went 'underground' and continued to be used in secret, resulting in the Merkabah (Flying-chariot) literature, which itself later gave rise to the Kabbalah school of Judaism. At each stage the literature became more metaphysical and spiritual, resulting in stranger and stranger texts for the uninitiated, much of which can be seen in the various additions and redactions to the Revelation of Metatron.
The contents of the chapters of the Ascension of Moses that have survived to the present show that the Ascension is an earlier version of the Revelation of Metatron, and the original protagonist of the story, later redacted to Rabbi Ishmael. There are several parallels between the stories of Moses and Metatron in the Ascension, and the stories of Ishmael and Metatron in the Revelation, however, the Revelation includes several heretical concepts that the original redactor and author of Chapter 16 did not want to ascribe to Moses and therefore used the popular Merkabah pseudonym Ishmael. The date of the original redaction is also difficult to determine, as Aher is a heretic in the Talmuds and Tosefta, and so the derogatory nick-name could have been adopted from the Talmud or Tosefta at any point. Nevertheless, if the original work was Rabbi Elisha's (Aher's) Sepher Hekhalot, it would have likely been redacted before the Babylonian Talmud's version of the story, which did not bother to name him. By that point, the text would have been by a generally unknown author, and there would have been no reason to redact his name from it. This would place the original redaction sometime before 450 AD, and likely in Byzantine Palestine.
