15.  And he that talked with me had a golden reed to measure the city, and the gates thereof, and the wall thereof.

16.  And the city lieth four square, and the length is as large as the breadth.  Ami he measured the city with the reed, twelve thousand furlongs:  the length, and the breadth, and the height of it are equal.

17.  And he measured the wall thereof, a hundred and forty and four cubits, according to the measure of a man, that is, of the angel.

Vs. 15-17.—­The apostle borrows the symbols and language of preceding prophets, especially those of Ezek. (xl. 3,) and Zech. (ii. 1.) The “furlongs” measured by the “reed,” indicate a city of vast dimensions; and being “four square,” each side would be about fifteen hundred miles!  And as the “length and breadth and height of it are equal,” we are hereby taught that no gross conceptions are to be formed in our imaginations, since a city fifteen hundred miles high, is utterly inconceivable.  The instruction intended to be conveyed to us by the vast dimensions, and precious materials of this city may be, the incomprehensible nature and transcendent glory of heaven. (1 Cor. ii. 9.) A cubit, as the word signifies, “is the measure of a man” from his elbow to the end of his middle finger.  The measure of the wall, in height or breadth, was a hundred and forty-four cubits, or the twelve tribes, as before, multiplied by the twelve apostles; for the idea of a cube, as the most perfect symbol of symmetrical form, seems to be intended.

18.  And the building of the wall of it was of jasper:  and the city was pure gold, like unto clear glass: 

19.  And the foundations of the wall of the city were garnished with all manner of precious stones.  The first foundation was jasper; the second, sapphire; the third chalcedony; the fourth, an emerald;

20.  The fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.

21.  And the twelve gates were twelve pearls:  every several gate was of one pearl:  and the street of the city was pure gold, as it were transparent glass.

Vs. 18-21.—­The “jasper, gold and glass,” are here all combined; though their natural properties and chemical elements are so different.  Glass is clear, transparent, but brittle; gold is solid and shining, but opaque.  In heaven, the saints shall know more than we can now imagine.  The glass will be all gold.  As the eye sees an object through glass at a glance, so the saints in heaven will perceive truth without the tedious process of comparison and reasoning.  The gold will be all glass.  All these symbols are intended to show to the devout reader, that the antichristian harlot is incomparably eclipsed by the glory of the Lamb’s bride,—­having “no glory, by reason of the glory that excelleth.”—­The twelve “precious stones” which “garnished the foundations of the wall of the city,” are an allusion to those of Aaron’s breastplate of judgment. (Exod. xxviii. 17-20;) indicating that the Urim and Thummim, the light and perfection of glory, shall be there, superseding the oracle and Shekinah:  for one thing is peculiar to this city by which it is distinguished from the old Jerusalem,—­no temple.