Jerusalem is one that is built like a city that has been joined together in oneness,

Jerusalem is a city “joined together in oneness.” Houses were built close together, as if ‘joined in oneness.’ This was the usual arrangement for a city in ancient times. Compact and surrounded by strong fortifications, such a city was easier to defend than a large, sprawled-out metropolis would have been. The city’s defenders did not have to cover an extensive area, leaving certain parts vulnerable to enemy attack. Furthermore, Jerusalem was surrounded by mountains and steep valleys on the east, south and west, greatly limiting the space available for building. Since the city’s inhabitants were living close together and depended upon one another for help and protection, the physical closeness could well represent the spiritual unity of the whole nation when all the tribes of Israel assembled for worship.