Isaiah 24:23, “Then the moon will be confounded and the sun ashamed, for YHWH of hosts reigns on Mount Zion and in Jerusalem, and His glory will be before His elders.”
What does it mean for the moon to be confounded and the sun ashamed? I think we can take this in two ways. The first might be that the moon and sun—i.e., the heavenly lights—are darkened. On the day when YHWH of hosts reigns from Mount Zion and reveals His glory to the assembled elders, on that day the moon and sun will be confounded, will be made dark. And that is precisely what we see in Matthew 27:45: “Now from the sixth hour there was darkness over all the land (or “earth”) until the ninth hour.”
When Jesus of Nazareth is lifted up on the cross, YHWH is manifest in His glory before the elders of the people who have assembled around Him (indeed, the elders of Israel are here revealed to be no elders, while the Lord’s Mother and the Beloved disciple are, in some sense, revealed to be the true elders of the people). And, just as Isaiah says, the moon and sun are confounded in that moment, the sky is turned to darkness on the Day of YHWH’s glory.
But there is another way to take this language as well, namely, that the moon and sun are confounded and ashamed by the superior light of the glory of YHWH. This is an image that John picks up in His depiction of the New Heavens and Earth when he says that there is no need for sun or moon because the glory of God—shining in the lamp of the Lamb—illumines all the world (Rev.21:23). There again YHWH reigns from the mountain of Zion on the New Earth and His elders—all the redeemed—are gathered around Him, forever beholding His glory streaming to them in the face of the slain and risen Christ (Rev. 22:1-5).
However, ultimately these two depictions are the same reality. The darkening of the skies over Calvary is the physically perceptible dimming of the sun and moon before the radiance of the glory of God in the face of the slain and risen Lamb (Rev.21:23-22:3)…The skies of Calvary go dark because—like the Burning Ones, the Seraphim—the luminaries of heaven have bowed their heads and hidden their faces from the light of the unveiled glory of God, the very same glory that will—and even now does—fill the regenerated heavens and earth.
Indeed, we may say that Revelation 21:23-22:5 is John’s depiction of the spiritual reality he perceived on Calvary….the sun and moon are eclipsed by the glory of God in the face of Christ, the nations gather to the throne of God and of the Lamb, and from that throne flows out a river of living water to give life and healing to all the earth…..Yes, this is the New Heavens and New Earth, but this is also Calvary as perceived by the eyes of the Spirit. To those with eyes to see, the cross of Calvary is the radiant throne and life-giving center of the New Creation, and the throne of the New Creation by which the re-created universe is illuminated and from which its life and healing flow is the cross of Calvary.