The Outer Measurements
Once the guide has finished measuring the interior temple area, he brings Ezekiel out to measure the precinct all around from the east gate. Each side of the enclosure comes to five hundred cubits, forming a vast and regular perimeter. The surrounding wall is explicitly said to divide the holy from the common, making the meaning of all the chapter's measurements unmistakable.
N15ow when the man had finished measuring the interior of the temple area, he led me out by the gate that faced east, and he measured the area all around: 16With a measuring rod he measured the east side to be five hundred cubits long. 17He measured the north side to be five hundred cubits long. 18He measured the south side to be five hundred cubits long. 19And he came around and measured the west side to be five hundred cubits long. 20So he measured the area on all four sides. It had a wall all around, five hundred cubits long and five hundred cubits wide, to separate the holy from the common.