Revelation 21:12-14 "12 Also she had a great and high wall with twelve gates, and twelve angels at the gates, and names written on them, which are the names of the twelve tribes of the children of Israel: 13 three gates on the east, three gates on the north, three gates on the south, and three gates on the west. 14 Now the wall of the city had twelve foundations, and on them were the names of the twelve apostles of the Lamb."
Revelation 21:12-14 "12 Also she had a great and high wall with twelve gates, and twelve angels at the gates, and names written on them, which are the names of the twelve tribes of the children of Israel: 13 three gates on the east, three gates on the north, three gates on the south, and three gates on the west. 14 Now the wall of the city had twelve foundations, and on them were the names of the twelve apostles of the Lamb."
To clarify the question, why are the tribes written on the gates, and the apostles on the foundation, and not the other way around? What could "gate" and "foundation" signify?
I take this passage literally but would still like to try to grasp the metaphorical significance. I would appreciate an answer pointing to some reading on the subject.