Not only were the instructions for the new Temple to give hope to the exiles, but they were also given to help the people be ashamed of their sins.
Ezekiel 43:10-11 Son of man, describe to the people of Israel the Temple I have shown you, so they will be ashamed of all their sins. Let them study its plan, and they will be ashamed of what they have done. Describe to them all the specifications of the Temple—including its entrances and exits—and everything else about it. Tell them about its decrees and laws. Write down all these specifications and decrees as they watch so they will be sure to remember and follow them.
Indeed, the basic law of the Temple was holiness:
Ezekiel 43:12 And this is the basic law of the Temple: absolute holiness! The entire top of the mountain where the Temple is built is holy. Yes, this is the basic law of the Temple.
That temple, the one with those specifications, would never be built.
It meant the promise of God’s presence filling the Temple, a Temple that wasn’t built, could not come to pass.