'The Twelve' in the Bible

It has a wall, massive and high, with twelve large gates, and in charge of the gates were twelve angels. And overhead, above the gates, names were inscribed which are those of the twelve tribes of the descendants of Israel.

The wall of the city had twelve foundation stones, and engraved upon them were twelve names--the names of the twelve Apostles of the Lamb.

And the twelve gates were twelve pearls; each of them consisting of a single pearl. And the main street of the city was made of pure gold, resembling transparent glass.