John Gill Commentary Ezekiel 41:4

"And he measured the length thereof, twenty cubits, and the breadth, twenty cubits, before the temple: and he said unto me, This is the most holy place." — Ezekiel 41:4 (ASV)

So he measured the length thereof twenty cubits That is, of the most holy place, from east to west; which was the measure of it in Solomon's temple, (1 Kings 6:20) :

and the breadth twenty cubits before the temple : that is answerable or according to the breadth of the temple or holy place; which was also twenty cubits in breadth: this stood at the west end of it, and was equal in breadth to it; see (1 Kings 6:2 1 Kings 6:20) :

and he said to me, this is the most holy place ; the divine Person in human form said to the prophet, take notice of this building; this answers to the most holy place in the temple.

This was an emblem of the most holy and perfect state of the church on earth; it represents the New Jerusalem church state, that holy city, and into which nothing shall enter that defiles; and, as in the most holy place, the divine Shechaniah or majesty of God dwelt; so here will dwell in person the God-man and Mediator, the head of the church, our Lord Jesus; whose tabernacle will now be with men, in this perfect state, raised from the dead, and he will dwell among them: and as this most holy place in its dimensions is a foursquare, so is the holy city described; denoting its stability and perfection; see (Revelation 21:2Revelation 21:3Revelation 21:16Revelation 21:27) .