The Book of Jubilees', sometimes called Lesser Genesis (Leptogenesis), is an ancient Jewish religious work, considered one of the pseudepigrapha by Protestant, Roman Catholic, and Eastern Orthodox Churches. However, Jubilees is considered canonical by the Ethiopian Orthodox Church as well as Jews in Ethiopia, where it is known as the Book of Division (Ge'ez: Mets'hafe Kufale).

It was well known to Early Christians, as evidenced by the writings of Epiphanius, Justin Martyr, Origen, Diodorus of Tarsus, Isidore of Alexandria, Isidore of Seville, Eutychius of Alexandria, John Malalas, George Syncellus, and George Kedrenos. However, it was so thoroughly suppressed in the 4th century that no complete Hebrew, Greek or Latin version has survived. There is conjecture among western biblical scholars that Jubilees may be a rework of material found in the canonical books of Genesis and Exodus.

The Book of Jubilees claims to present "the history of the division of the days of the Law, of the events of the years, the year-weeks, and the jubilees of the world" as revealed to Moses (in addition to the Torah or "Instruction") by Angels while he was on Mount Sinai for forty days and forty nights. The chronology given in Jubilees is based on multiples of seven; the jubilees are periods of 49 years, seven 'year-weeks', into which all of time has been divided. According to the author of Jubilees, all proper customs that mankind should follow are determined by God's decree. (courtesy of wikipedia.com)