This means that the amount of Light that they receive in their Kli, being the will to receive, is already separated from the Creator…Thus, the only difference between them is that one is a “whole” and the other is a “part,” as a stone that is carved from a mountain.
Here, without dependence on our present level, we encounter something that differentiates us from His essence (Atzmuto). We take the “substance,” meaning the desire to receive, and clothe the form of the substance. This is to say, in that the desire to receive reacts to His essence, it receives some kind of form. But this form is also substance and not the filling in the usual sense of the word.
We can pour water from a bottle into a cup and so instead of the form of the bottle, the water takes on the form of the cup. But this change happens only in the world of our imagination, and in fact doesn’t exist because there is no fundamental change in the essence of the material itself.
In spirituality this is talking about the desire to receive, where its change is its fulfillment. We give names to the vessels and the Lights that are extended into the Partzuf. Each name is a structure consisting of the four letters, HaVaYaH (Yod-Hey-Vav-Hey), meaning the four phases that we learn.
And in continuation, everything depends on which level these phases are found, how they are mutually divided and connected, which form they receive from the all-inclusive infinite Light. In this world of Infinity is found some kind of perception of reality, the desire to receive, which is distorted and bent and changed in a particular way by the Light.
In this way, the substance of the desire always remains and it has this form or another that it receives from the Light. The forms are divided into four general forms: still, vegetative, animate, and speaking, in the spiritual sense, but also get all kinds of sizes and characters in all kinds of forms of relationships.
Therefore the Light influences the desire in all the possible structures of HaVaYaH that are found in the general system and the desire takes on some kind of form. And we are speaking about this object, about the substance and about the form clothing the substance. And this form can be Klipa (impurity) or Kedusha (sanctity). But the substance remains the same substance, a desire to receive.
The question is asked: Why do we call the form “Light”? It’s because I receive the changes from some cause that influences me. And according to the changes in me ,I can gradually become conscious of it. Essentially, I become conscious only of the relationship to me. This is the reason that the Creator is called: “Come and see” (Bo Re). Only I can see, perceive, this, and nobody else, and I perceive the form clothing the substance. The Creator “clothes” the creature and this makes it possible for me to call Him the Creator. For, in this manner, I can feel Him, come into contact with Him. He gave me my form.
And according to this, “From your actions we shall know You.” “Your deeds” is me. And through what You do with me, I become aware of You. Only in this way is spiritual attainment realized. All the rest is philosophy and erroneous.
From the 2nd part of the Daily Kabbalah Lesson 12/31/13, Writings of Baal HaSulam