This verse summarizes the measurements of verses 16-19.

He measured it on the four sides means Ezekiel’s guide measured the four sides of the Temple compound. New Century Version says “So he measured the Temple area on all four sides” (similarly New International Reader’s Version).

It had a wall around it …: See 40.5. The surrounding wall was five hundred cubits long and five hundred cubits broad, that is, 250 meters (840 feet) on each side. It was a “perfect square” (Contemporary English Version).

The function of the wall was to make a separation between the holy and the common. Good News Translation says “to separate what was holy from what was not” (similarly New International Reader’s Version, New Century Version), and Moffatt has “to mark the boundary between what was sacred and what was unconsecrated.” This clause may refer generally to things that were holy and things that were not, but it is better to take the holy to refer to the “the sanctuary” (King James Version), “the sacred area” (Revised English Bible), the whole Temple compound. The common refers to “ordinary” (Contemporary English Version) things that have not been “consecrated” (similarly New Jewish Publication Society’s Tanakh) for religious use (see the comments on 22.26). This clause may be rendered “This wall was there to separate the area that was fit for the worship of God from things that were not.”

Quoted with permission from Gross, Carl & Stine, Philip C. A Handbook on Ezekiel. (UBS Helps for Translators). Miami: UBS, 2016. For this and other handbooks for translators see here .