יחודא עילאה (Upper Unity) is a central concept in Jewish mysticism that refers to the highest level of Divine unity. It is specifically associated with the first verse of the שמע prayer: "Listen Israel, השם our God, השם is One."[1]
This entry is severely incomplete.
This unity describes the simple, absolute oneness of השם as He exists before the first צמצום (constriction). On this plane, the Divine essence is entirely beyond the structure of the ten ספירות (Divine emanations). This level of unity transcends any form of enumeration or calculation.
As stated in ספר יצירה: "Before One, what do you count?" This idea is echoed in the תיקוני זהר: "You are One, but not in enumeration."[2] This highlights a state of being so absolute that the very concepts of parts, attributes, or numbers do not apply.
The Upper Unity stands in contrast to יחודא תתאה (Lower Unity), which corresponds to the second line of the שמע, "Blessed is the Name of His glorious kingship forever and ever." The Lower Unity pertains to G-d's kingship and manifestation within the created worlds, after the צמצום.[3]