In Ezekiel 40-42, the prophet is taken on a tour of a Temple and he describes it in precise detail including its measurements and physical features. The context of this experience, coupled with the fact that this was clearly not a description of the first two Temples, tells us that this Temple that Ezekiel got a tour of is one that will feature prominently in the Millennial Kingdom.
The Millennial Kingdom, like other aspects of biblical truth, has been interpreted in many different ways. Some people say it’s metaphorical, and some say that we are living in it now, but the simplest and most straightforward reading of the Bible tells us that the Millennial Kingdom is a literal event that will happen in the future. And clearly, Ezekiel’s words in these chapters suggest this is the case. If the kingdom were metaphorical, why would God go to such great pains to show us the exact specifications, layout, and dimensions of this building? There would be no point in doing that if the third Temple is just a metaphor. And if we are living in the Millennial Kingdom now, where then is this Temple that Ezekiel was shown? The location today features a Mosque, not what Ezekiel described. There is no way to reconcile this that makes any sense.
No, the simplest and best explanation for these chapters is that Ezekiel was shown the actual third Temple that will be present during the Millennial Kingdom, and God has recorded and preserved this vision so that we can see, through these words, that the promised Millennial Kingdom is a real thing. It’s coming. It’s literal. And it’s going to be spectacular.