Until we clarify our desire to enjoy and reveal the whole system of connections and qualities in it, it seems to be just a desire to us, nothing special. However, when its depth is revealed, we see just how complicated this system is.
This is how in quantum physics, scientists penetrate deeper and deeper into matter, each time revealing a whole world within, consisting of smaller and smaller elementary particles that seemed inseparable before. Similarly, we penetrate deeper and deeper into the desire to receive pleasure.
What do we see in it? We see how the Upper Light that created the desire to enjoy influenced it and created the four phases of the Direct Light in it. Since the Light entered the desire to receive, during these four phases, it builds its own structure in it.
In the desire to receive itself, there is nothing except the desire. However, the Light creates differentiations in it according to the five phases of Aviut (the thickness, coarseness of the desire): Shoresh, Aleph, Bet, Gimel, Dalet (root, one, two, three, four), as well as the Sefirot, worlds, Partzufim, lines, and an infinite number of types of connections and forms, each of which has its own characteristics. There is an infinite number of differences, and they all come from the Light.
Therefore, the more we reveal the desire to receive, the more we reveal the Light, the Creator, and His nature. However, we reveal Him from the material, the desire to receive, and this is called "form clothed in matter."
We do not reveal the Creator Himself. We reveal the actions that He has performed in the matter, and from these actions, we know the Creator. As it is written, "From Your actions, I shall know You."
We penetrate into the matter itself. The Creator brought Himself into the matter, we reveal ourselves in that same matter, and there we encounter the Creator. Therefore, Atzmuto (His Essence) remains unattainable.
From the 2nd part of the Daily Kabbalah Lesson 1/2/2011, “Introduction of The Book of Zohar,” Article “Yitro (Jethro)”