I have included a visual here so that you won’t get lost in the temple’s description. The presentation itself is somewhat tedious, but at least four things stand out.
First, this is a grand structure, grander even than the temple of Solomon’s day. Second, it exists among a people who regard God with the upmost reverence, who are ashamed of their sins, and who have turned from those sins (43:7-10). Third, the focus of the temple is the altar, where sacrifice is made to the Lord. Fourth, this temple is the residence of the Lord and sign that the Lord has returned to His people. Just as the Lord departed from the temple through the east gate, so he returns through it in chapter 43.
There is no indication this temple was ever to be built. Having promised the restoration of God’s people and their protection, the temple described in these chapters reveals the return of God to dwell among His people. His dwelling is glorious, and therefore so are His people.