What O.T passages do premillenialists believe to be about the Millennial Kingdom? What passages do premilleialists, that is, those who believe the "1000 year reign of Christ to be a literal event to occur only after the second coming of Christ, find in the Old testament that they believe to be prophesying about the Millennial Kingdom?
I am Word of Faith we are pretribulational dispensational premillennialism. We believe Zechariah 14 and Ezekiel 43-48 are all used to describe the millennium kingdom of Christ on the earth. Zechariah 14 describes the return of Christ with His saints from a governmental standpoint. Gill's Exposition of the Entire Bible Zechariah 14:5 holds the idea the millennial reign is being discussed throughout this chapter. Ezekiel 43-48 largely focuses on the Glory of God returning to Israel and the return of their priesthood during the millennial reign. Its difficult to point to one reliable source which states this but many independent sources say as much on google and I know it is what is taught by Billye Brim in her School of Eschatology on Ezekiel which is no longer available for purchase. While Rev 20 is on the same topic since it is describing a different aspect of the return of Christ it doesn't directly correlate to either chapters from the Old Testament.

Zec 14:5  And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the LORD my God shall come, and all the saints with thee.

Gill's Exposition of the Entire Bible Zechariah 14:5

and the Lord my God shall come; the Lord Jesus Christ, who is truly God, and the God of his people; and who will appear to be so at his second coming, which is here meant, by raising the dead, gathering all nations before him, and separating them; by bringing to light all secret and hidden things; judging the whole world, and executing the sentence on them; and particularly by taking his own people to himself:
and all the saints with thee: the Targum, and the Septuagint, Syriac, and Arabic versions, read, &quot;with him&quot;; meaning either the holy angels; so Aben Ezra, Kimchi, and Ben Melech; who will attend him partly for the glory of his majesty, and partly for terror to the wicked, and also for service; or rather glorified saints, the spirits of just men made perfect, whom Christ will bring with him to be united to their bodies, which will now be raised, and to be with him in the new heavens and new earth, which will now be formed, and to be presented to him, and dwell with him, during the thousand years.

and

Eze 44:3  It is for the prince; the prince, he shall sit in it to eat bread before the LORD; he shall enter by the way of the porch of that gate, and shall go out by the way of the same.