This essayed discourse assumes the reader has prior familiarity with the story brought down in Lurianic Kabbalah of how the Infinite Light withdrew to make a space for the emanations and creations, along with what transpired soon after the withdrawal. This discourse is intended to be mystically abstract and not meant for light reading. However, if you are seeking lighter inspirational posts, you have indeed come to the right address. There are plenty of them on this blog to enjoy. Just scroll around a bit and you'll find them.
I enjoyed learning from the Ramchal quotations in “Da’at Elokim” what a couple of terms I’ve seen in my past struggles studying the “Tahiru Ila’ah” actually mean. I’ve learned that “Avir Kadmon”, primordial atmosphere, means the untouched afterglow . I also learned that “Olam HaMalbush”, the realm of enclothment, means the reality which serves as the membrane around the “line of light”.   This membrane modulates the light from the line, so it can interact with the afterglow in order to differentiate it’s undifferentiated light. Very nifty indeed!
Now I wonder whether the membrane is the same layer as Reb Shlomo Antebi discussed, when he described the skin of the line of light as a deeply indented portion of the membrane around the afterglow (i.e. the membrane bordering the Infinite Light and the remaining afterglow). He explained that it is like poking one’s finger into a balloon. The finger’s indentation in the balloon is surrounded by the skin of the balloon itself. Could it be that the Ramchal’s realm of enclothment that layer or is it yet another layer? Logic seem to indicate that, if so, it should be layered on the outside of (and not lining the inside of) the indented membrane. The reason is because the indented membrane already has a history of not differentiating the light of the afterglow. So if there’s a second layer, it should be placed on the outside. Since differentiating is its main function, it should be placed where it can interact with what it is changing ~ in this case the undifferentiated afterglow.
On the other hand, it might not be a “second layer”, but, rather the same membrane whose properties have been transformed by the line of light. Just to insert itself into the zone of the afterglow, there needs to be something inherently different about the line of light that make’s it do something different from the rest of the Infinite Light. The rest of the Infinite Light is so masculine polarized that it withdrew from the feminine core of the afterglow. Since it is the feminine is within the masculine and the masculine with the feminine which causes attraction, it must be that such deep engagement with the afterglow, to the point of entry, can only be coming from an aspect of the Infinite Light which has a higher feminine polarity than the rest of the Light. It could be that there’s a polarization and differentiation even within the post-withdrawal Infinite Light to differentiate out a higher degree of femininity into a line of light. Typically, the story after the Infinite Light’s withdrawal concentrates on the polarization and differentiation within the area of the afterglow. However, there’s a surprise here. There seems to be yet another polarization and differentiation within the Infinite Light itself to form the line of light. Otherwise, how could it be?
Once this “differentiated Infinite Light” has contact with the membrane around the afterglow, it can differentiate that membrane itself. It’s bending inward, a change in shape and location, is indication of its own differentiation in response to contact with newly differentiated Infinite Light. It’s a “domino effect”, the differentiation in one sets off the differentiation in the other. By caving in, the part of the outer membrane approaches in closer contact with the most intensely feminine core of the afterglow, becoming more similar to it or becoming more feminine. Similarly, in the female uterus the zone of most feminine essence, where ova is produced, is most deeply lodged, while the aspects that most directly engage maleness are closer to the outer surface or on the outer surface.
Once the membrane differentiates, it can serve as the realm of enclothment, continuing the differentiation, again as a “domino effect”, into the afterglow, forming surrounding layers and realms ~ as contact with the differentiated differentiates.
This latter scenario seems most logical to me. The reason is because just to form the line of light there needs to be a differentiation. Then the membrane needs to differentiate: (A) in response to contact with something differentiated, namely the Infinite Light which became the line of light and (B) in order to cave in, i.e. change its shape. (As an interesting aside, in order for a part of the membrane to further feminize, some portion of the unpenetrated membrane has to further masculinize ~ as contact with the differentiated differentiates.)
Since the membrane differentiates and the surrounding afterglow soon after differentiates into layers and layers, both the membrane and the surrounding layers modulate the light of the line radiating further out into the space of the afterglow. The membrane itself is a direct modulation, while the surrounding levels are additional modulations layered upon the initial modulation. So at this point, whether the realm of enclothment the membrane or a surrounding layer is just a question of semantics. Both exist and it’s only a question of which one carries the label. The straightforward understanding of the Ramchal is that it would be the initial indented membrane. There’s no compelling reason that I know of, at this time, to think otherwise.
This tie in with the magic of the womb to affect differentiation. The outer surface of the female reproductive apparatus is more masculinized in order to meet the outer surface of the male reproductive apparatus which is more feminized. However, deeper in the female apparatus is more feminine. That’s why what’s male cannot reach there.
Rabbi Yehuda Fataya in his commentary “Bait Lechem Yehuda” explains that what’s feminine, i.e. the womb, is the primal element of fire. As fire forges what was separate into a whole, so does the womb. The womb performs “tikkun”, i.e. mending what’s separate, because what doesn’t yet relate to each other is now brought together into an interactive relationship. This is done by burning away the barriers between the separate elements and allowing each to incorporate an element of the other; thereby, creating bridges which promote cooperation instead of contention.
Though speculative, this also might be the mystery of inoculation. By incorporating a little bit of the disease, the relationship between the person and the disease is no longer contentious. Additionally, there might be a hidden positive to having this spark added to the person in manageable doses.
So mutual incorporation of differentiated elements of others, becomes the key to interaction and cooperation. Now I see why “Binah”, the womb concept, is related to the growth process called “teshuva”, which amounts to improving relationships with the Creator and other people. “Teshuva” is about breaking the barriers, proper cooperation through proper interaction. This is really a process of differentiation. The raw undifferentiated self has to grow and develop through further differentiation by incorporating new differentiated elements in harmonious proportions. This is the “tikkun” process or “teshuva”; it’s healthy growth!
 A commonly used acronym for Rabbi Moshe Chaim Luzzatto.
 See “Da’at Elokim”, pages 18 & 19.
 “Tahiru Ila’ah” might translate well as “Celestial Brightness”. However, this translation does not convey anything about it. That’s why I was reluctant to use the translation in the body of the discourse. Essentially, the “Tahiru Ila’ah” is a series of transitional stages between the pure Infinite Light and the “tzimtzum”, the withdrawal to make an empty space for emanations and creations.
 Known in the parlance of Kabbalah as the “reshimu”, literally “the trace”.
 Known in the parlance of Kabbalah as the “kav”, literally “the line”.
 This particular realm of enclothment refers to the one after the withdrawal. The Ramchal seems to speak of another realm of enclothment prior to the withdrawal in the following footnote of “Da’at Elokim”.
 In his lectures in Autumn of 2001.
 “Tree of Life”, Gate 20, Chapter 11 - see comment with the heading, “Further inward is the mystery of the backside ...”.