Isaiah 40:4 Commentary: Every Valley Exalted

Isaiah 40 opens a new movement in the book. The first thirty-nine chapters carry a heavy tone of judgment, the people's sin, the coming exile, the fall of Jerusalem. But chapter 40 begins with a startling shift: “Comfort, comfort my people.” The Cambridge Bible describes this section as “breathing the spirit of new-born hope and enthusiasm.” The historical situation has changed. From Assyrian threat in Isaiah's own day, the prophet's gaze leaps forward to the Babylonian exile and beyond. The people are in captivity, but God is not finished with them.

The highway imagery would have been vivid to ancient readers. When an Eastern monarch traveled, work crews went ahead to level the road. Valleys were filled with rubble and earth. Rocky outcrops were broken apart. The goal was a smooth, direct route that let the king travel in honor and speed. Isaiah takes this practical custom and turns it into a theological promise. God himself will clear a path through the wilderness, not just a physical road for the return from Babylon, but a way for his own glorious arrival. Jamieson-Fausset-Brown note that John the Baptist later took up this language: “John's duty was to bring back the people to obedience to the law and to remove all self-confidence, pride in national privileges, hypocrisy, and irreligion.”

The word עָקֹב deserves attention. Its root עקב appears in Genesis for Jacob gripping Esau's heel (Gen 25:26). The verb can mean to come from behind, to be elevated like a mound, or to be arched like a hill. Gesenius, cited by Barnes, takes it this way. The word does not primarily describe moral crookedness but physical terrain, and terrain that Jesus, in his incarnation, will come to flatten.

The supplied commentaries note no significant textual variants for Isaiah 40:4 that would change the meaning of the verse. Keil and Delitzsch observe a minor Masoretic variation in the pointing of גֶּיא ('valley'): some editions read גֵּיא (with tzere), while the standard text has גֵּיא (with tzere) or גֶּיא (with segol). They cite the Brescia, Pesaro, and Venice editions and a codex of Luzzatto as witnesses. This affects the vowel pointing only and does not alter the sense of the word.

The church has read Isaiah 40:4 primarily through the lens of John the Baptist. All four Gospels quote Isaiah 40:3, and by extension the leveling imagery of verse 4 became the sound of Advent. Preachers from Augustine through the Reformers used the valleys and mountains to describe the spiritual landscape of the human heart, pride that must fall, despair that must be raised. The Geneva Bible notes simply, with its characteristic terseness: “The crooked shalbe streight, and the rough places plaine.” In the Eastern tradition, the verse is sung in hymns of preparation for the Nativity and Theophany, calling the faithful to make their souls a worthy path for the Lord. The image of a highway through the wilderness also inspired generations of African American spirituals, where the “rough places plain” became a promise that the journey ahead, however hard, would finally be smooth under God's hand.

Three-point outline

1. God prepares what he plans. Before deliverance comes preparation. God does not simply announce salvation and leave his people to work it out. He goes ahead, clearing the road, making the path smooth. This is grace before the journey even begins.
2. Every obstacle is his concern. Mountains and valleys, rough places and steep hills, nothing is too big or too small for God to address. The same verse that handles mountains also handles the crooked footpath. His preparation is both majestic and minute.
3. Humility before the coming King. The leveling language functions spiritually. What is high and proud will be brought low. What is low and humble will be lifted up. The way of the Lord is prepared not by our achievements but by our readiness to receive him.

Five-point outline

1. The herald's call, a voice in the wilderness announces that God is on the move. Preparation begins with proclamation.
2. The reversal of terrain, valleys rise, mountains fall. God specializes in turning our expectations upside down.
3. The removal of hindrances, the word עָקֹב (steep places) and רְכָסִים (rough places) name specific kinds of difficulty. God knows what blocks each of us.
4. The level highway, מִישׁוֹר (level ground) and בִּקְעָה (plain) are the result. After God's work, the path is not just passable but good.
5. The revelation of glory, verse 5 follows: when the way is prepared, all flesh sees the glory of the Lord. The road exists for the King, not the travelers.

Illustration hooks

• A city repaving a major road before a parade for a visiting head of state, the disruption is temporary, the honor is the point.
• A family clearing out a spare room and making repairs before hosting an elderly parent who needs to move in, the work of preparation is an act of love.
• A gardener breaking up hard soil and removing rocks before planting, the rough ground must change before anything new can grow.

Questions your congregation is asking

• If God is preparing a way, why does my life still feel blocked and difficult?
• How do I know whether the obstacles I face are from God, from my own sin, or simply part of life?
• Does this promise apply to me personally, or only to Israel and the coming of Christ?

This verse sits at the hinge of Isaiah's prophecy, where judgment gives way to comfort. It is poetry that sounds like a construction project. Before you discuss, read Isaiah 40:1-5 aloud as a group. Let the rhythm of the passage settle. Notice how the herald's voice commands attention.

Discussion questions

1. Read Isaiah 40:3-5. What picture do these verses paint of God coming to his people? What feelings does the imagery stir in you?
2. Barnes says the language is “taken from the march of a monarch at the head of his army.” How does this change the way you read the promise?
3. The Hebrew word for 'valley' (גֶּיא) means a narrow gorge, not an open meadow. Why might the prophet choose a word that suggests tight, confined spaces?
4. In verse 4, the steep places (עָקֹב) become level ground (מִישׁוֹר). Clarke and Barnes argue this is about terrain, not morality. Does that make the spiritual application stronger or weaker? Why?
5. Both Matthew 3:3 and Luke 3:4-6 apply this passage to John the Baptist. In what ways did John's ministry 'level' the ground for Jesus? What needed to change in Israel for the Messiah to be received?
6. What might a 'mountain' or 'valley' look like in your own life today, something that keeps you from seeing God clearly or following him well?
7. This passage ends with the revelation of God's glory (v. 5). How does the removal of obstacles lead to seeing God more clearly? Is it always true that cleared paths produce clearer vision?