31 are to be the gates of the city. Named after the tribes of Israel, three gates are to serve the north site: one named the Reuben Gate, one named the Judah Gate, and one named the Levi Gate.
Ezekiel 48:31 Cross References - ISV
Isaiah 26:1-2
Isaiah 54:12
12 And I’ll make your battlements of rubies, and your gates of jewels, and all your walls of precious stones.
Isaiah 60:11
11 Your gates will always stand open by day or night, and they will not be shut, so that nations will bring you their wealth, with their kings led in procession.
Revelation 21:12-13
Revelation 21:21
21 The twelve gates were twelve pearls, and each gate was made of a single pearl. The street of the city was made of pure gold, as clear as glass.
Revelation 21:25
25 Its gates will never be shut at the end of the day—because there will be no night there.