Isaiah 40:5 promises that the LORD’s glory will be revealed so that every person alive will see it at the same time. The prophet is confident about this because God himself has spoken it, so the promise rests on God’s word rather than on human expectation. The verse was written by Isaiah, who speaks on God’s behalf to the exiled people of Judah, and it opens a message of comfort after a long season of judgment.
The LORD’s glory shall be revealed, and all flesh shall see it together; for the mouth of the LORD has spoken it.”
Isaiah 40:5 (WEB)
What Isaiah 40:5 Means
The phrase “the LORD’s glory shall be revealed” points to God showing who he really is. In the Old Testament, glory often refers to God’s weight, splendor, and presence, the honor that belongs to him alone. To say it “shall be revealed” means it is not hidden forever. A time is coming when what has been obscured will be plainly seen.
The next phrase, “all flesh shall see it together,” widens the promise beyond Israel. “All flesh” means all human beings, not just the chosen nation. The word “together” suggests that no one will be left out or left behind. Everyone will witness the same revelation.
The verse ends by grounding everything in God’s own speech: “for the mouth of the LORD has spoken it.” Isaiah is not guessing or hoping. The certainty comes from God’s word. The verse does not spell out the timing or the manner of the revelation, and it does not promise any particular person a private experience. It promises that God’s glory will be displayed openly, and that his word makes this sure.
The Context of Isaiah 40:5
Isaiah 40 begins the second main section of the book, often called Second Isaiah. Traditionally the book is attributed to the eighth-century prophet Isaiah, though many scholars think chapters 40 to 66 were shaped later, during or after the Babylonian exile. The original audience was a people who had lost their city, their temple, and much of their sense of security. The opening verse of the chapter tells the prophet to “comfort” Jerusalem and announce that her punishment is over.
Just before verse 5, a voice calls for a highway to be prepared in the wilderness, and valleys and mountains are leveled. This imagery describes a royal procession, the kind a king would prepare for his return to his capital. Verse 5 announces what that procession will reveal: God himself coming to be seen. Verses 6 to 8 then contrast the frailty of human beings, who fade like grass, with the enduring word of God. That contrast explains why the revelation in verse 5 depends on God’s word and not on human strength.
Key Phrases in Isaiah 40:5
Psalm 19:1
The heavens declare the glory of God. The expanse shows his handiwork.
(WEB)
This verse says that the heavens declare the glory of God, showing that God’s glory is already visible in creation. Isaiah 40:5 looks ahead to a fuller and more universal display of that same glory, so Psalm 19:1 helps you see that the promise is rooted in what God has already made known.
Isaiah 55:11
So is my word that goes out of my mouth: it will not return to me void, but it will accomplish that which I please, and it will prosper in the thing I sent it to do.
(WEB)
This verse compares God’s word to rain and snow that accomplish what they are sent to do. It parallels Isaiah 40:5 by affirming that when God speaks, his word does not return empty, which gives confidence that the revelation of his glory will certainly happen as he has said.
A Short Prayer From Isaiah 40:5
Lord, you have spoken, and your word stands when everything else fades. Thank you that your glory is not hidden forever and that you intend to show who you are to all people. When I feel uncertain about what you are doing, remind me that the promise rests on your mouth and not on my understanding. Help me to trust your timing and to look for your faithfulness in the ordinary places of my day. Let your word shape how I see the world, and let me wait with hope for the day when your glory is fully seen. Amen.
