Solomon Rubin has written:

'Sod ha-sefirot' -- subject(s): Symbolism of numbers

'Berosi ha-kasdi' -- subject(s): Antiquities

It started with Abraham the Patriarch four thousand years ago, who wrote a book called Sefer Yetzira (The Book of Creation). The next important work is The Book of Zohar, written in the second century CE. The Zohar is followed by the works of the Ari, a renowned 16th century Kabbalist. And the twentieth century saw the appearance of the works of Kabbalist Yehuda Ashlag. Ashlag’s texts are best suited for our generation. They, as well as other Kabbalistic sources, describe the structure of the upper worlds, how they descend and how our universe, with everything that’s in it, came into existence. Yehuda Ashlag’s textbook Talmud Eser Sefirot (The Study of the Ten Sefirot) is designed as a study aid with questions, answers, materials for repetition and explanations. This is, if you will, the physics of the upper worlds, describing the laws and forces governing the universe on the spiritual realm. For further info: www.kabbalah.info

Yehudah Ashlag has written:

'Talmud 'eser ha-sefirot' -- subject(s): Cabala

'The Kabbalah' -- subject(s): Cabala, History and criticism

'Sefer Matan Torah' -- subject(s): Doctrines, Judaism, Cabala

'In the shadow of the ladder' -- subject(s): Cabala, History

'Matan Torah =' -- subject(s): Cabala

'Sefer Shelabe ha-sulam' -- subject(s): Commentaries, Talmud, Fasts and feasts, Judaism, Bible

'Sefer Even sapir' -- subject(s): Cabala, Dictionaries, Hebrew

'An entrance to the Zohar' -- subject(s): Cabala, Zohar

Through a careful study of the Tanakh, Jewish sages[who?] identified ten Sephirot (ten being the number of divine perfection). At their fundamental level, the ten Sephirot are a step-by-step process illuminating the Divine plan as it unfolds itself in our world. They are known by the following names/characteristics from highest to lowest:[citation needed] # Keter - Crown - Divine Plan/ Creator/ infinite light/ Ehyeh Asher Ehyeh - I AM THAT I AM (Supreme/ Total Consciousness) # Chokmah - Divine Reality/ revelation/ Yesh me-ayin - being from nothingness (Power of Wisdom) # Binah - Understanding/ repentance/ reason (Power of Love) # Chesed - Mercy/ Grace/ Love of (intention to emulate) God (Power of Vision) # Gevurah - Judgment/ strength/ determination (Power of Intention) # Tipheret - Symmetry/ balance/ compassion (Creative Power) # Netzach - Contemplation/ Initiative/ persistence (Power of the Eternal Now) # Hod - Surrender/ sincerity/ steadfastness (Intellectual/ Observational Power) # Yesod - Foundation/ wholly remembering/ coherent knowledge (Power of Manifesting) # Malkuth - Lower Crown - Kingdom/ physical presence/ vision and illusion (Power of Healing/ Accomplishment/ Level of Realization of Divine Plan) http://en.wikipedia.org/wiki/Sephirot

Traditionally, the Shield of David (or Magen David) represented King David's shield, though this is only a legend. It arose as a Jewish symbol in the Middle Ages and today represents the Nation of Jews all over the world.
It is the symbol of Judaism religion.