The Zohar, Introduction, Article “The Vision of Rabbi Hiya,” Item 56: …“At that time, He kicks 390 firmaments, and all are startled and frightened of Him.” … This is the hint in the Masach called “firmament” … There aren’t 400 but 390, with ten missing, Malchut de Malchut. This is why he calls the firmament, “390 firmaments.”
The vessel of our soul is characterized by the size of the desire. This size is called “Aviut.” If we perform the First Restriction on it (Tzimtzum Aleph), then the Direct Light (Ohr Yashar) comes to us and we reject it, raising the Reflected Light (Ohr Hozer).
The Direct Light is equal to the desire because our desire reveals the degree of Light or pleasure that it corresponds to. Therefore, in reality the Light does not have to “come.” Now, when I have not made a restriction yet, I do not feel that I am in the Light, the Creator. But having carried out the condition of the First Restriction I will immediately feel that I am in the Light.
This is the Direct Light that “comes” to me. It pushes on me, knocking to come inside, and then the first thing I do is I reject it, raising the Reflected Light. The Reflected Light indicates the rigidity of the screen (Kashiut), while the Direct Light indicates its Aviut. We are talking about the screen because it is the connecting link between the soul and the Creator, being in the middle between them.
The desire itself, Malchut, divided into four parts, each containing ten Sefirot, each of which also consists of ten. Altogether there are 400. We cannot correct the lowest part, Malchut de Malchut, “the stony heart.” Her ten Sefirot are excluded from the general count and thus there are 390 remaining Sefirot or screens that The Zohar calls “firmaments.”
From here we see that in order to hold on to the connecting thread, we have to translate The Zohar’s language, which is still incomprehensible to us, to the language of Kabbalistic terms.
From the 1st part of the Daily Kabbalah Lesson 12/23/10, The Zohar