Revelation 21:15-17

15The angel who spoke with me had a golden measuring rod to measure the city and its gates and walls. 16The city lies foursquare, with its width the same as its length. And he measured the city with the rod, and all its dimensions were equal—12,000 stadia1 in length and width and height. 17And he measured its wall to be 144 cubits,2 by the human measure the angel was using.