זוהר דברים — דף רפג ע”א

The Zohar develops the secret of the tree of knowledge of good and evil: good is Metatron, king of angels, and evil is Samael, prince of demons. The Holy Blessed One rules over both, and it is through the merit of Torah and commandments that Israel elevates spiritually. The Zohar then describes the seraphim and the Shekhinah singing 'Holy, holy, holy,' as well as the mystery of souls ascending and descending within the spiritual hierarchy.