“The Book of Jasher, a work – as we are told by a very learned Hebrew divine, of New York – composed in Spain in the twelfth century as a “popular tale”, and that had not “the sanction of the Rabbinical College of Venice”, is full of kabalistical, alchemical, and magical allegories. Admitting so much, it must still be said that there are few popular tales but are based on historical truths. The Norsemen in Iceland, by Dr. G. W. Dasent, is also a collection of popular tales, but they contain the key to the primitive religious worship of that people. So with the Book of Jasher. It contains the whole of the Old Testament in a condensed form, and as the Samaritans held, i.e., the five Books of Moses, without the Prophets.
Although rejected by the orthodox Rabbis, we cannot help thinking that, as in the case of the apocryphal Gospels, which were written earlier than the canonical ones, the Book of Jasher is the true original from which the subsequent Bible was in part composed. Both the apocryphal Gospels and Jasher, are a series of religious tales, in which miracle is heaped upon miracle, and which narrate the popular legends as they first originated, without any regard to either chronology or dogma. Still, both are cornerstones of the Mosaic and Christian religions. That there was a Book of Jasher prior to the Mosaic Pentateuch is clear, for it is mentioned in Joshua, Isaiah, and 2 Samuel.
Nowhere is the difference between the Elohists and Jehovists so clearly shown as in Jasher. Jehovah is here spoken of as the Ophites held him to be, a son of Ilda-Baoth, or Saturn. In this Book, the Egyptian Magi, when asked by Pharoah “Who is he, of whom Moses speaks as the I am”; reply that the God of Moses “we have learned, is the Son of the Wise, the Son of ancient kings” (chapter lxxix, 45).
Now, those who assert that Jasher is a forgery of the twelfth century – and we readily believe it – should nevertheless explain the curious fact that, while the above text is not to be found in the Bible, the answer to it is, and is moreover, couched in unequivocal terms. At Isaiah xix., 11, the “Lord God” complains of it very wrathfully to the prophet and says: “Surely the princes of Zoan are fools, the council of the wise counsellors of Pharoah is become brutish; how say ye unto Pharoah, I am the Son of the Wise, the Son of ancient kings”, which is evidently a reply to the above.
At Joshua x., 13, Jasher is referred to in corroboration of the outrageous assertion that the sun stood still, and the moon stayed until the people had avenged themselves. “Is not this written in the Book of Jasher”, says the text. And at 2 Samuel, i., 19, the same book is again quoted. “Behold”, it says, “it is written in the Book of Jasher.” Clearly, Jasher must have existed; it must have been regarded as authority; must have been older than Joshua; and since the verse in Isaiah unerringly points to the passage above quoted, we have at least as much reason to accept the current edition of Jasher as a transcription, excerpt, or compilation of the original work, as we have to revere the Septuagint Pentateuch, as the primitive Hebraic sacred records.
At all events, Jehovah is not the ancient of the ancient, or “aged of the aged”, of the Sohar; for we find him, in this book, counselling with God the Father as to the creation of the world. “The work-master spoke to the Lord. Let us make man after our image” (Sohar). Jehovah is but the Metatron, and perhaps, not even the highest, but only one of the Aeons; for he whom Onkelos calls Memro, the “Word”, is not the exoteric Jehovah of the Bible, nor is he Jahve 
, the Existing One.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 