We must remember that the entire wisdom of Kabbalah is founded on spiritual matters that do not take up time or space. They are not subject to change or absence and all the changes that are spoken of in this wisdom do not imply that the first form becomes absent and is replaced by a different form. The above change rather implies an additional form, while the first does not move from its place (Baal HaSulam, The Study of the Ten Sefirot).
Question: What is this spiritual reality that has neither time nor space? How can one imagine it practically, not philosophically?
Fulfillment is the light that fills a desire, which feels itself being empty. And once it is full of light, it feels itself as being perfect.
The entire creation consists of these two substances, the place and the fulfillment.
Question: How should we imagine this? Should we imagine that this happened once upon a time or is happening now?
Answer: It is best to imagine that it happened in the past. Just like the Ari wrote: Know that before the emanated beings were emanated and the created beings created, an upper, simple light had filled the entire reality.
What does reality mean? It means a place. Then the Ari explains that it is the desire to feel light as fulfillment. The quality of light is to fill this desire in order to give it pleasure.
All this was happening before the Big Bang, before our corporeal reality appeared.
From KabTV’s The Study of the Ten Sefirot (TES), 8/14/22