And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon, which are the names of the twelve tribes of the children of Israel: Had a wall great and high - An almighty defense.
Twelve gates - A gate for every tribe of Israel, in the vicinity of which gate that tribe dwelt; so that in coming in and going out they did not mix with each other. This description of the city is partly taken from Ezekiel 48:30-35.
In Synopsis Sohar, p. 115, n. 27, it is said: "In the palace of the world to come there are twelve gates, each of which is inscribed with one of the twelve tribes, as that of Reuben, of Simeon, etc.: he, therefore, who is of the tribe of Reuben is received into none of the twelve gates but his own; and so of the rest."