Albert Barnes Commentary Isaiah 24:23

"Then the moon shall be confounded, and the sun ashamed; for Jehovah of hosts will reign in mount Zion, and in Jerusalem; and before his elders shall be glory." — Isaiah 24:23 (ASV)

Then the moon shall be confounded — The heavenly bodies are often employed in the sacred writings to denote the princes and kings of the earth. These expressions are not to be pressed too exactly, as if the sun denoted one thing and the moon another; rather, they are general poetic expressions designed to represent rulers, princes, and magistrates of all kinds (Joel 2:30–31).

Shall be confounded — This means to be covered with shame. That is, it will appear to shine with diminished beauty, as if ashamed in the presence of the superior glory that would shine around it. The meaning is that when the people returned to their land, the theocracy would be restored. Then, the magnificence of the kings and other civil rulers would be dimmed by the superior splendor of the reign of God. There is probably a reference here to the time when Yahweh would reign in Jerusalem through, or by means of, the Messiah.

In Mount Zion — (see the note on Isaiah 1:8). This would take place after the captivity, and preeminently under the reign of the Messiah.

And before his ancients — That is, before the elders of the people; in the presence of those entrusted with authority and rule.

Gloriously — He would reign gloriously when His laws were respected and obeyed, when His character as King and Ruler was developed, and when, under His scepter, His kingdom was increased and extended. The prophet's eye was fixed on this glad prospect; this was the bright and splendid object in the ‘vision’ that served to relieve the darkness that was coming upon the nation. Present calamities can be borne with the hope that Yahweh will reign more gloriously hereafter, and that the ultimate result of all things will be to exalt Yahweh in the sight of the nations.

It may be added that when Yahweh, by the Messiah, reigns over all the earth, all the glory of princes and monarchs will be dimmed. The renown of their wisdom, power, and plans will be obscured by the superior splendor of God's wisdom, as He reigns through His Son over the human race.

Come, that blessed day; and speedily let the glory of the moon be confounded and the sun ashamed, and let all inferior magnificence fade away before the splendor of the Sun of Righteousness!