Sefer Yetzirah, or the Book of Formation, is among the earliest and most important treatises on Jewish mysticism. Traditionally ascribed to the patriarch Abaraham or the first century CE Rabbi Akiba ben Joseph, Sefer Yetzirah explores how the universe was created through "32 wondrous ways of wisdom", including the ten numbers or aspects of God in Kabbalistic thought, and twenty-two letters, corresponding to early philosophic and proto-scientific ideas about the planets, elements and constellations.
