And I will lay thy windows with pearls. By these metaphors he shows that the condition of the Church, as has been formerly said, will be far better than at any former period. The Church is compared to a building, which is customary in every part of Scripture. (Jeremiah 24:6; Matthew 16:18.) For this reason he now draws a picture of a costly and magnificent structure. But it ought to be remarked, that the Prophet represents God as the architect of this building; for this work ought to be entirely ascribed to him alone. But it may be asked what the Prophet means by "carbuncles, sapphires, pearls," and other kinds of jewels; for by a similar metaphor Paul meant doctrine. "As a wise architect," says he, "I have laid the foundation." And again, "If any man build on this foundation, gold, silver, precious stones, wood, hay, stubble, every man's work shall be made manifest." (1-Corinthians 3:10-13) Whether or not this be the Prophet's meaning, will appear from the following verse.

And I will make thy windows - The word rendered here 'windows' is rendered by Jerome propugnacula - 'fortresses,' bulwarks, ramparts; and by the Septuagint, Επαλξεις Epalcheis - 'Bulwarks,' or rather, pinnacles on the walls. The Hebrew word שׁמשׁות shı̂mâshôt) is evidently derived from שׁמשׁ shemesh (the sun); and has some relation in signification to the sun, either as letting in light, or as having a radiated appearance like the sun. Gesenius renders it, 'notched battlements, the same as sun, or rays of the sun.' Faber (Hebrew Archaeol., p. 294) supposes that the name was given to the turrets or battlements here referred to, because they had some resemblance to the rays of the sun. I think it prob able that the prophet refers to some radiated ornament about a building, that had a resemblance to the sun, or to some gilded turrets on the walls of a city. I see no evidence in the ancient versions that the word refers to windows.
Of agates - Agates are a class of silicious, semi-pellucid gems, of many varieties, consisting of quarts-crystal flint, horn-stone, chalcedony, amethyst, jasper, cornelian, etc., variegated with dots, zones, filaments, ramifications, and various figures. They are esteemed the least valuable of all the precious stones. They are found in rocks, and are use, for seals, rings, etc. (Webster.) The Hebrew word כדכד kadekkod, from כדד kâdad, to beat, to pound, and then to strike fire, seems to denote a sparkling gem or ruby. It is not often used. It is rendered by Jerome, Jaspidem. The Septuagint, Ιασπιν Iaspin - 'Jasper,' a gem of a green color. It may be observed that it is not probable that such a stone would be used for a window, for the purpose of letting in light.
And thy gates - See Revelation 21:21 - 'And the twelve gates were twelve pearls; every several gate was of one pearl.' The gates of the city would be made of most precious stones.
Of carbuncles - The carbuncle is a beautiful gem of a deep red color, with a mixture of scarlet, called by the Greeks anthrax, found in the East Indies. It is usually about a quarter of an inch in length. When held up to the sun it loses its deep tinge, and becomes exactly the color of a burning coal (Webster). Hence, its name in Greek. The Hebrew name אקדח 'eqeddâch is derived from קדח qâdach, "to burn," and denotes a flaming or sparkling gem. The word occurs nowhere else in the Hebrew Bible.
And all thy borders - All thy boundaries; or the whole circuit of thy walls. See Revelation 21:18 - 'And the building of the wall of it was of jasper.' The idea is, that the whole city would be built in the most splendid manner. Its foundations and all its stones would be laid in the most precious cement; its turrets, towers, battlements, gates, and the circuit of its walls, would be made of the most precious gems. In general, there can be no doubt that this is designed to represent the future glory of the church under the Redeemer, and perhaps also to furnish an emblematic representation of heaven (compare Revelation 21:2). Kimchi supposes that this may possibly be taken literally, and that Jerusalem may be yet such as is here described. Abarbanel supposes that it may refer to the time when the Oriental world, where these gems are principally found, shall be converted, and come and join in rebuilding the city and the temple.
But the whole description is one of great beauty as applicable to the church of God; to its glories on earth; and to its glory in heaven. Its future magnificence shall be as much greater than anything which has yet occurred in the history of the church, as a city built of gems would be more magnificent than Jerusalem was in the proudest days of its glory. The language used in this verse is in accordance with the Oriental manner. The style of speaking in the East to denote unexampled splendor is well illustrated in the well-known Oriental tale of Aladdin, who thus gives his instructions: 'I leave the choice of materials to you, that is to say, porphyry, jasper, agate, lapis lazuli, and the finest marble of the most varied colors. But I expect that in the highest story of the palace, you shall build me a large hall with a dome, and four equal fronts; and that instead of layers of bricks, the walls be made of massy gold and silver, laid alternately: and that each front shall contain six windows, the lattices of all which, except one, which must be left unfinished and imperfect, shall be so enriched with art and symmetry, with diamonds, rubies, and emeralds, that they shall exceed everything of the kind ever seen in the world' (Pictorial Bible).

And I will make thy windows of agates,.... Some sort of which stones, Pliny (x) says, were valued for their clearness like glass; but the stone which bears this name with us is not clear and lucid enough to make windows of. The Septuagint, Vulgate Latin, Syriac, and Arabic versions, render it, "of jasper", a stone more fit for that purpose; and it is interpreted of the jasper in the Talmud (y); so "the light" of the New Jerusalem is said to be like unto the "jasper stone", Revelation 21:11. Some take the crystal to be meant, which suits well with windows; the word (z) for which has its name from the sun, because by means of them the rays and light of the sun are let into a house, and illuminate it; these in a figurative sense may design the ministers of the Gospel, who are the lights of the world, especially of the church; and the word and ordinances administered by them, by means of which the light of spiritual knowledge, joy, and comfort, is let into the churches, and into the souls of men, from Christ, the sun of righteousness. The phrase signifies, that in the latter day their ministrations should be very clear and bright, and be greatly owned, and be very successful: "and thy gates of carbuncles"; precious stones so called from their fiery flaming colour. The gates of the New Jerusalem are said to be so many pearls, Revelation 21:21 which there, as here, signify the entrance into the church of God, which is through Christ, who is the door into it, and through faith in him, which works by love; these gates will be open in the latter day to receive many, who will come in great numbers, and are called "praise", Isaiah 60:11, which will be expressed in very warm and lively strains of love and affection, of which the carbuncle may be a symbol:
and all thy borders of pleasant stones; true believers, called "lively stones", and who are pleasant in the sight of God and Christ, and are taken pleasure in by one another; see Psalm 102:14. The Septuagint and Arabic versions render it, "thy wall", which agree with Revelation 21:18, where the wall of the New Jerusalem is said to be of jasper.
(x) Nat. Hist l. 37. c. 10. (y) T. Bab. Bava Bathra, fol. 75. 1. (z) "a radice, quae solem significat", Sanctius,

windows--rather, "battlements"; literally, "suns"; applied to battlements from their radiated appearance.
agates--rather, "rubies."
carbuncles--literally, "sparkling gems"; the carbuncle when held to the sun becomes like a burning coal.
all thy borders--rather, "thy whole circuit," consisting of precious stones. The glory of the Church on earth, when the Hebrew Church, according to the original design, shall be the metropolis of Christendom.

Agates - The proper signification of the Hebrew names of precious stones is unknown to the Jews themselves. It may suffice us to know that this was some very clear and transparent, and precious stone. Thy borders - The utmost parts or walls.