The most fundamental theme underlying all Hasidic theory is the immanence of God in the universe, often expressed in a phrase from Tikunei haZohar, (Aramaic: "no site is devoid of Him"). This panentheistic concept was derived from Lurianic discourse, but greatly expanded in the Hasidic one. In the beginning, in order to create the world, God contracted ("Tzimtzum") his omnipresence, the "Ein Sof", leaving a Vacant Void (), bereft from obvious presence and therefore able to entertain free will, contradictions and other phenomena seemingly separate from God himself. These would have been impossible within his original, perfect existence. Yet, the very reality of the world which was created in the Void is entirely dependent on its divine origin. Matter would have been null and void without the true, spiritual essence it possesses. Just the same, the infinite "Ein Sof" cannot manifest in the Vacant Void, and must limit itself in the guise of measurable corporeality that may be perceived.