Testaments of the Twelve Patriarchs

An excerpt from the INTRODUCTION - General Character of the Book:
The book purports to give the last words, at the approach of death, of each of the twelve patriarchs to his sons. It is evident that the general idea of the book is based upon Jacob's last words to his sons as recorded in Gen. xlix. 1-27. Just as Jacob portrays the character of his sons and declares to them what shall befall them, so in our book each of the patriarchs is represented as describing, in some sense, his own character and as foretelling what shall come to pass among his posterity in the last times. From this latter point of view the book partakes of the character of a prophetic-apocalyptic work. In six of the testaments, those of Reuben, Simeon, Judah, Dan, Naphthali and Joseph, there is a certain correspondence between our book and Gen. xlix. regarding the characters of the patriarchs; as for the remaining six patriarchs no such correspondence exists.