Isaiah 40:31

Analysis & Commentary

But they that wait upon the LORD shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; and they shall walk, and not faint. This celebrated promise concludes a magnificent chapter contrasting human weakness, mortality, and limitation with divine majesty, eternality, and infinite power. The Hebrew verb qavah (קָוָה, "wait") encompasses far more than passive endurance or reluctant patience; it signifies active, expectant hope characterized by confident trust—like a rope being twisted together, creating exponentially greater strength through interweaving individual strands. This waiting involves deliberate dependence on God's timing and provision, patient anticipation of His fulfillment, and confident trust in His character and promises. It is the antithesis of anxious striving, self-reliant effort, or passive resignation.

The object of waiting is "the LORD" (YHWH, יְהוָה), the covenant name revealing God's eternal, self-existent nature and unwavering faithfulness to His promises. This is not generic waiting or vague spirituality but covenant-specific hope grounded in God's revealed character and documented redemptive acts throughout Israel's history. The verb's imperfect form suggests ongoing, habitual action—those who characteristically wait upon Yahweh, not merely in isolated crisis moments but as a consistent lifestyle of dependence, trust, and expectation. This waiting assumes God's goodness, sovereignty, wisdom, and perfect timing, refusing to run ahead of His providence or lag behind His revealed will.

The promise is "shall renew their strength" (yaḥaliphu ḵoaḥ, יַחֲלִיפוּ כֹחַ). The verb ḥalaph literally means "to pass on," "change," or "exchange," frequently used for changing garments (Genesis 41:14, Leviticus 27:10). Here it conveys the profound idea of exchanging human weakness for divine strength—a supernatural replacement, not mere human recuperation, positive thinking, or self-improvement. This is God's strength substituted for human inability, omnipotence replacing frailty. The noun koaḥ denotes not just physical vigor but vital energy, moral capability, spiritual power, and capacity for life's demands. This strength encompasses physical endurance, emotional resilience, spiritual vitality, and moral courage. It is comprehensive empowerment for holistic faithful living.

Three carefully chosen metaphors illustrate this renewed strength, arranged in descending order from highest to most common, yet paradoxically from easiest to most difficult. First, "mount up with wings as eagles" (yaʿalu ʾever kannešarim, יַעֲלוּ אֵבֶר כַּנְּשָׁרִים) references the eagle's (nesher, likely referring to the griffon vulture common in Israel) remarkable ability to soar effortlessly on thermal currents, rising to extraordinary heights without exhausting wing-flapping. Naturalists have documented these birds reaching altitudes exceeding 10,000 feet, remaining aloft for hours with minimal energy expenditure. This represents transcendent victory over circumstances, rising above life's storms through divine enablement, experiencing supernatural joy and triumph despite adverse conditions. It pictures the believer lifted above earthly trials into heavenly perspective and power.

Second, "they shall run, and not be weary" (yaruṣu velo yigaʿu, יָרוּצוּ וְלֹא יִיגָעוּ) depicts sustained exertion without exhaustion or burnout. Running requires more effort than soaring but less than walking's steady, prolonged endurance. This middle metaphor represents seasons of intense spiritual activity, extraordinary service, concentrated ministry effort, or crisis response maintained by divine strength rather than human adrenaline. It describes supernatural enabling for exceptional demands—the ability to serve, minister, witness, and labor beyond natural capacity without collapse or depletion. This is the experience of missionaries in difficult fields, pastors in demanding ministries, believers in persecution, and parents in overwhelming circumstances who find divine strength for sustained extraordinary effort.

Third, "they shall walk, and not faint" (yeleku velo yiʿapu, יֵלְכוּ וְלֹא יִיעָפוּ) portrays the daily grind, the ordinary faithfulness, the mundane obedience that characterizes most of Christian life. Walking seems easier than running, yet sustained walking over long distances tests endurance more profoundly than brief intense exertion. Marathon runners testify that the final miles prove hardest; long-distance hikers know that steady walking mile after mile, day after day demands greater stamina than sprinting. This metaphor describes faithful daily obedience, persistent godliness, consistent witnessing, regular prayer, continued Bible study, ongoing service, and sustained holy living year after year, decade after decade. God's strength enables not only extraordinary exploits but faithful, ordinary, daily obedience—perhaps the greatest miracle of all. The progression from soaring to running to walking paradoxically moves from spectacular to mundane, yet from easier to harder, teaching that God's strength suffices equally for both crisis and routine, for both extraordinary service and ordinary faithfulness.

Historical Context

Isaiah 40 marks a dramatic shift in the book's tone, beginning the "Book of Comfort" (chapters 40-66). While chapters 1-39 pronounce judgment on Judah's sins, chapter 40 opens with "Comfort ye, comfort ye my people"—a transition from warning to hope. Written in the late 8th century BC, these prophecies look forward to exile's end and ultimate restoration through the Servant of the Lord, whom New Testament writers identify as Christ.

The opening verses envision heralds announcing Jerusalem's liberation after Babylonian captivity (586-538 BC), over a century future. Verses 1-11 describe preparing a highway through the wilderness for God's people—imagery later applied to John the Baptist preparing for Messiah (Matthew 3:3, Mark 1:3, Luke 3:4, John 1:23). This context of promised restoration frames verse 31's encouragement, addressing those who feel abandoned and exhausted.

Verses 12-26 present Scripture's magnificent contrast between God's infinite power and human impotence. God measures oceans in His palm, weighs mountains in scales, numbers every star (astronomers estimate 10²⁴), and controls nations as dust on scales. Nations are "as a drop of a bucket" (v. 15), earth's inhabitants "as grasshoppers" (v. 22), rulers reduced to nothing (v. 23). This cosmic perspective on God's sovereignty provides theological foundation for verse 31—those waiting on this God access limitless resources.

The eagle imagery resonated deeply in ancient culture. Eagles (likely griffon vultures, nesher, Israel's largest flying birds) soar to incredible heights effortlessly, remaining aloft for hours. Aristotle documented their flight in Historia Animalium; Pliny described their vision and soaring in Natural History. Biblically, eagles represent strength (2 Samuel 1:23), swiftness (Jeremiah 4:13), renewal (Psalm 103:5), and divine care. Deuteronomy 32:11 depicts God bearing Israel "on eagles' wings" from Egypt, connecting deliverance with this imagery.

Church history demonstrates this verse's sustaining power. Desert fathers like Anthony cited it regarding spiritual ascent. Medieval mystics including Bernard of Clairvaux applied it to spiritual growth stages. Reformation martyrs found courage here—Hugh Latimer, John Bradford, and William Tyndale quoted it before execution (1555-1536). Wesley referenced it in sanctification sermons. Modern missionaries draw strength during opposition—Hudson Taylor cited it during China Inland Mission trials; Jim Elliot quoted it before martyrdom (1956).

The verse appears in numerous hymns. "On Eagle's Wings" (Michael Joncas, 1979) makes it contemporary worship's centerpiece. "God Will Take Care of You" (Civilla Martin, 1904) and "Great Is Thy Faithfulness" (Thomas Chisholm, 1923) echo its theology. Contemporary artists including Michael W. Smith, Amy Grant, and Hillsong have recorded songs based on this text, demonstrating enduring relevance across twenty-seven centuries.

Questions for Reflection

• What does 'waiting on the Lord' look like practically and specifically in your current season and circumstances—how does it differ fundamentally from passive resignation to circumstances or anxious striving in your own strength?
• Are you trying to 'run' or 'soar' in your own human strength in areas where God is clearly calling you to stop, wait, and exchange your weakness for His supernatural power and wisdom?
• Which metaphor (soaring above circumstances, running without weariness, or walking faithfully without fainting) best describes where you most desperately need God's renewed strength right now, and what does this reveal about your current spiritual state?
• How does the theological context of Isaiah 40:12-26 (God's incomparable greatness, infinite power, and absolute sovereignty over nations and nature) fundamentally change your perspective on whatever is currently draining your strength and overwhelming your resources?
• What specific spiritual practice or discipline of 'waiting upon the LORD' could you implement consistently and intentionally to regularly access this promised renewal of strength in your daily walk with God?