<p>21:21- see on Mt. 7:6.</p><p><i>And the twelve gates were twelve pearls. Each of the separate gates was of one pearl</i>- The gates are open constantly (:25), and even if shut, the glory passing through the pearl would have given the effect of the pearl being transparent. This fits with the otherwise strange image of transparent gold (see on :18). The gates are open; but why are there gates, therefore, and why are they effectively transparent? It is in order to teach something to the nations who witness Christ's return. They must recognize that there is indeed a wall and gate to be passed through, but it is effectively open and transparent to them, such is the Lord's will that they should enter in.</p><p><i>And the street of the city was pure gold, as if it were transparent glass- </i>Gold cannot by nature be transparent. John is struggling in words to convey what he saw and the impressions which arose. As with the language of demons, we have an example here of how the Bible uses human language and at times records things from the limited perspective of observers on earth.</p>