Julius Wellhausen's
documentary hypothesis asserts that the
Torah was compiled in the fifth century BC from several independent, contradictory, hypothetical (nonextant) documents, including the
Jahwist,
Elohist,
Deuteronomic, and
priestly sources and the
Book of Generations. Advocates of this hypothesis, such as
Richard Elliott Friedman, attribute Levi's biblical genealogy to the "Book of Generations". Others attribute Moses's birth narrative, which also mentions Amram and Jochebed, to the earlier "Elohist source". According to this theory, the Levite genealogy is a myth to explain away the fact that four different groups claimed descent from Levi—the
Gershonites,
Kehathites,
Merarites, and
Aaronides. Since Aaron could not have been a brother to Gershon, Kehath, and Merari, since he was the son of one of Kehath's sons, he had to belong to a following generation. The hypothetical reconstruction of the "Elohist source" mentions only that both parents were Levites without identifying their names (). Some scholars suspect that the "Elohist source" attributes to Moses both
matrilineal and
patrilineal descent from Levites in order to enhance his religious credentials. ==Family tree==