By Joe David
Jerusalem first comes to or attention in II Samuel, chapter 5 where King David takes it from the Jebusites and makes it his capital. In the next chapter he brings the Ark of the Covenant there, and later it is where Solomon builds the temple, and his own palace. From then on Jerusalem is the center of worship of the Israelitish church. It is the place where the Lord was presented in the temple as a baby, where He tarried to talk to the priests at age twelve, where He cleansed the temple, had the last supper, was crucified and then rose. It is a central place in both the old and new Testaments.
The city of Jerusalem was built on Mount Zion, the highest point of the mountains of Judea. A city in the Word represents doctrine, the organized knowledge of the truths of the church. Mountains represent love of the Lord and the consequent worship. Jersualem on Mount Zion signifies the doctrine of love to the Lord, and how it governs your life.
This is why David was led to make Jerusalem the most important city of the land, and why all worship was conducted there. And this is also why Jeroboam was condemned for introducing idol worship in Samaria.
In the Book of Revelation, John’s vision of the city New Jerusalem descending from God is a prophecy of a new dispensation of doctrine coming from the Lord, some of which you may read in the references list below.
450. Having breastplates that were fiery, hyacinthine and sulfurous. This symbolizes their fanciful and illusory arguments springing from a hellish love and their own intelligence, and from the attendant lusts.
Breastplates symbolize the arguments people use to do battle for faith alone (no. 436). Fire symbolizes heavenly love, and in an opposite sense, hellish love (nos. 452, 468, 494). Hyacinthine symbolizes intelligence springing from a spiritual love, and in an opposite sense, intelligence springing from a hellish love, which is one's own inherent intelligence, as explained below. And sulfur symbolizes lust arising from that hellish love and expressed through their own inherent intelligence (no. 452). It follows from this that breastplates fiery, hyacinthine and sulfurous have the symbolic meaning stated.
 The reason their arguments in defense of faith alone are thus described is that all those people who believe themselves to be justified by faith alone, which is to say, absolved from sins, never give any thought to repentance, and an impenitent person engages in nothing but sins. All sins, moreover, spring from and so draw their character from a hellish love, from one's own inherent intelligence, and from the attendant lusts; and people caught up in them not only act on them, but they also speak, indeed think and will, in conformity with them, and accordingly reason and argue in conformity with them. These are who they are because they are their life; but who they are is a devil, and their life a hellish one.
In actual fact, however, people who live a moral life solely for the sake of themselves and the world do not know this. The reason is that although they inwardly are such as described, in outward appearances they are like people who live a Christian life. But they should know that when anyone of them dies, he comes into his interior life, because it is the life of his spirit, and he is his internal self. Moreover, his inner character then accommodates his outward one to itself, and they become alike. Consequently the moral virtues of these people's life in the world then become like the scales of fish that are scraped away.
The case is altogether different with people who regard the precepts of a moral life as Divine, and who make them at the same time civil precepts because they are expressive of a love for the neighbor.
 Hyacinthine symbolizes intelligence springing from the affection of a spiritual love because this color takes its hue from the redness of fire and the whiteness of light; and fire symbolizes love, and light intelligence. This intelligence is symbolically meant by the hyacinthine blue in the coverings and veils of the tabernacle (Exodus 26:31, 36; 27:16), and in Aaron's ephod (Exodus 28:6, 15); by the cloth of hyacinthine blue placed on the ark, table, lampstand, and altar [in the tabernacle] when the people prepared to journey (Numbers 4:6-7, 9, 11-12); and by the blue stuff in Ezekiel 27:7, 24.
On other hand, intelligence springing from the affection of a hellish love is symbolically meant by hyacinthine in Ezekiel 23:
Oholah (or Samaria) played the harlot... and she doted on her lovers, the neighboring Assyrians, clothed in hyacinthine blue..., horsemen riding on horses. (Ezekiel 23:4-6)
Thus is described a church which by the reasonings of its own inherent intelligence had falsified the Word's truths.
And in Jeremiah:
They are altogether foolish and grow stupid; the teaching of vanities is wood. Beaten silver... is brought from Tarshish..., the work of the craftsman and the hands of the metalsmith; hyacinthine blue and purple are their clothing, all the work of skillful men. (Jeremiah 10:8-9)
The work of the craftsman and the hands of the metalsmith, and all the work of skillful men, symbolize here that they spring from their own inherent intelligence.