I wanted to include this section from one of Henry Corbin's works here on my blog because it helped me to understand certain Quranic verses that would have otherwise remained a complete mystery to me - particularly Sura 18:84
The historian Tabari (9th century) has preserved for us some of the earliest information available about a mysterious region, which his description enables us to identify as the "Earth of the Emerald Cities." Two cities situated there - Jabarsa and Jabalqa- to which the traditions we shall study here add a third city, Hurqalya; the name Hurqalya is then used to designate this mystic country as a whole...
Jabarsa and Jabalqa, Tabari tells us are two emerald cities that lie immediately beyond the mountain of Qaf. Like those of Heavenly Jerusalem, their dimensions express quaternity, the symbol of perfection and wholeness. The surface of each is a square, the sides measuring twelve thousand parasangs. The inhabitants do not know of the existence of our Adam, nor of Iblis, the Antagonist; their food consists exclusively of vegetables; they have no need of clothing, for their faith in God makes them like angels, although they are not angels. Since they are not differentiated by sex , they have no desire for posterity. Lastly, all their light comes to them from the mountain of Qaf, while the minerals in their soil and the walls of their towns (like those of the archetypal paradise of Yima) secrete their own light. This indication already puts us on the way to establishing the identity of the mountain with the mysterious cities. It is said, in fact, that in this mountain "there is neither sun, nor moon, nor stars." Now we know that in the Ptolemaic system a characteristic of the ninth Sphere, which comprises the totality of the celestial Spheres and communicates diurnal movement to them , is that it is a heaven without constellations. Moreover, traditions specifically describe the mountain Qaf as the mountain surrounding our universe and as formed entirely of emerald, the reflection of which produces the green color (which to us looks blue) of the celestial vault. Or again, it is the rock (sakhra) forming the keystone of the celestial vault and imagined as being composed of emerald and as casting a reflection on the mountain of Qaf. What the visio smaragdina perceives her is, therefore , the cosmic mountain encircleing and overhanging our earthly habitat; the cosmic mountain was also what was perceived as encompassing the the visible horizon of Eran-Vej, in medio mundi, at the very place where the Chinvat Bridge projected from a high peak to join this cosmic mountain, whose ascent led the soul to the real of infinite Lights.
Now the geographer Yaqut expressly affirms that the mountain of Qaf was once called the Elburz. Indeed, it is the very same mountain which the "mother" of all the mountains of the world... And it is also the one climbed by the pilgrims of the spirit - as in Suhrawardi's "Recital of the Occidental Exile," for example - to reach the emerald rock looming before them like the translucent side of a mystical Sinai. And there, as at the entrance to the Chinvat Bridge of the Mazdean dramaturgy of the soul, the meeting with the archetypal Figure takes place, the celestial Person from whom the terrestrial "I" originates. Therefore the mountain of Qaf marks the boundary between two worlds, the one visible and the other invisible to the senses. In order to penetrate into the cities hidden on its further side, the mystical pilgrim must have passed beyond the evidence of the sense and common norms, must have faced the ordeals symbolized by the long journey in the Darkness across the distances that separate him from the Earth of the emerald cities.
Of course, insofar as the mountain of Qaf only lends its name to the the ancient Elburz, its primordial Image has been projected also on spaces of empirical geography (the Caucasus and its foothills on Iranian soil), which then become the theater of mythical events. On the other hand, as a primordial Image, it always marks the extremity of the world, and is inaccessible to men. To reach it, it would be necessary to walk for four months "in the Darkness"; that is why Alexander's progress through the region of Darkness is that of the archetypal spiritual hero, in Avicenna's "Recital of Hayy ibn Yaqzan," as well as in the exegesis of the Quranic Sura 18:84, describing how Alexander's Quest led him to the extreme Occident and the extreme Orient of the universe. Beyond, a region begins that includes many other cities (a country white as silver, forty days' travel in length , inhabited by angels; another country, of gold, seventy countries of musk, each ten thousand days' journey in length and breadth, etc.). In short, to penetrate into these Earths is to gain access to the intermediate climate of the "celestial souls" that move the Spheres and are preeminently endowed with pure Imagination, not depending on the senses. It is the "eighth climate," into which , as into Eran-Vej, one does not penetrate with the organs of sensory perception, but by passing through the "Source of Life", at the psycho-cosmic center.
Here we find our direction in a brief reference to the schema of the world that takes definite shape in Avicenna's cosmology. This schema divides the totality of thinkable being into a cosmic Occident and a cosmic Orient. We have already recalled percisly that this cosmic Orient is not to be sought in the East on our maps, but in the "polar dimension." In fact this Orient is the celestial pole, the "center" of all conceivable orientation. It is to be sought in the direction of the cosmic North, that of the "Earth of Light".
The "Occident" represents the sensory material world , and it is twofold: there is the "climate" of sublunar terrestrial matter, that off our material Earth, subject to generation and dissolution; and there is the "climate" of the celestial matter, that of the Spheres, consisting of an etheric substance, diaphanous and incorruptible, but still , however, deriving from the physical. The "Orient" begins from the climate of the soul: at the celestial Pole , at the emerald rock. This spiritual sun rises for the pilgrim and this dawn reveals to him the perspective of an entirely new universe, wherein are ranked successively the souls summoned to govern human bodies for a time; then the Souls whose mission it is to communicate the movement of their desire and their love to the celestial Spheres, and who are called celestial Angles (Angeli coelestes); finally, the Intelligences, who are respectively , the objects of this love and what are designated spiritual Angels or Cherubim (Angeli intellectuales). The characteristic that distinguishes Avicenna's cosmology from that of Averroes is percisly that the former includes in its structure this world of celestial Souls, in whose image the human soul is constituted, but which, unlike it, do not possess the organs of sensory knowledge. On the other hand, they are endowed with active Imagination. They even possess it in so pure and perfect a degree that their Imagination, independent, unlike ours, of sensory date, is entirely true and never weakened. Therefore, the representations that the Angels of celestial Souls may make of their universe corresponds to the situation of the human soul when its active Imagination, purified and trained, has become the imganatio vera, its organ of meditation.
So what the souls shows to itself, in this case again, as in the case of the Mazdean Imago Terrae, is percisly its own image: the Earth it projects, the Earth of Hurqalya, is the phenomenon of the Earth in its pure state, since it directly reflects the Image premeditated by the soul. The universe thus imagines, free from misleading and perishable sensory data, is therefore a function of the pure transcendental Imagination and depends only on its categories, which are a priori archetypal Images. That is why this universe is called 'alam al-mithal, the world of archetypal Images, the world of autonomous imaginative forms, or again, the world of correspondences and symbols, that is a world symbolizing with the sensory, which it precedes, and with the intelligible, which it imitates. It is a mixed world, mediating between the sensory and the intelligible; it is the center of the worlds, or again the "intermediate Orient", between the "near Orient," which is the human soul rising to consciousness of itself, and the spiritual "far Orient" constituted by the pleroma of cherubic Intelligences. Thus, as pictured by our Spirituals in their own way, it represents this intermediate kingdom between pure matter and pure Spirit, and intermediary necessary in order to validate the visionary events, the entire dramaturgy of which the should is both the subject and the scene, everything that sensory perceptions have no means to govern, impair, or supplement; everything to which the skepticism of the rational consciousness is opposed, as it is to all essentially individual cases that can neither be classified nor gauged by ordinary standards.
-Henry Corbin "Spiritual Body and Celestial Earth From Mazdean Iran to Shi'ite Iran"