Just as a gold ring is made of gold, everything in the cosmos is made of the ousia (being).
This means everything arises from the Ein Sof (dreamless sleep) appears in dreaming and waking. After this it returns to the Ein Sof. This is the Nous (changing of the 3 worlds or bodies, garments in gnostic terms). This means the Ousia (being nature) is the heart or unending essence of everything. Ein Sof (means unending).
Oh wow, this is another complex post. Actually its simple, basically the ousia (being essence) is the blackboard of the cosmos and the mind which creates the forms is the chalk. I am using the gold ring as the tool to explain this. I need to point out I am not the first to use gold as the example of the essence. You will find references in Buddhist sutras, say the sutra of Maitreya and other sources mentioning gold. Basically the ring is the object and the gold is the essence. Basically its objects and substance or substance monism. Confused, pls keep following these posts for further illumination.