This book is a mathematical, analytical and philosophical analysis of the Cabalistic texts the 'Sepher Yetzirah' and the five books of the 'Zohar'. It is considered by some to be the 'missing' sixth book of the Zohar and the author's book 'The Kabbalah Decoded' is the seventh. Through illustration, analysis of ancient texts and educated supposition the authors specualte the 'Manna Machine' was a device which provided a food source for the disenfranchised Jewish people from Egypt. The 'manna' itself was a form of blue-green algae rich in beta-carotenes (much like spirulina) and when combined with leaven bread (no yeast) formed the stable food stuff for the 40 years of 'wandering in the desert' by the ancient Jews. Both books are very well researched and an excellent read.