Waiting on the Lord in Isaiah 40:31 describes looking to God for strength while endurance is still needed. The chapter addresses people who suspect their case has been overlooked. It answers with the strength of the Creator given to people who are weary.
Read the complaint just before the promise
In verse 27, Jacob and Israel say that their way is hidden from the LORD and their claim has gone unnoticed. The names identify a people. Their complaint gives waiting an ache. Something has gone on long enough for them to wonder whether God sees it.
The reply asks whether they have heard that the LORD is the everlasting God, the Creator of the ends of the earth. In the earlier part of the chapter, the people hear words of comfort. Near the end, they are given a reason to hope in the character of the one who speaks it.
What the Creator does with strength
God does not become tired in verse 28. The next verse says he gives strength to the weary and increases the power of the weak. Keep those sentences together. The Creator’s strength has a direction in the passage. It reaches people whose own reserves are limited.
Verse 30 says that even young people grow tired and stumble. Their youth gives readers a clear example of the limits of ordinary vigor. The people addressed in verse 31 rely on strength received. Waiting or hoping names the posture of people looking to the giver.
Eagles, runners, and walkers
The eagle is the most conspicuous picture. The two images that follow bring the promise close to the ground. The people run without growing weary and walk without fainting. The last image is ordinary movement sustained. It deserves the same attention as the soaring.
Sometimes renewed strength looks like capacity for a particular task you expected would overtake you. Isaiah’s closing picture gives language for that quieter kind of continuation. It also leaves the waiting visible. The promise reaches a people who still have a course to travel.
Read it as a reply to someone weary
Read the complaint in verse 27 slowly, then read God’s description in 28–31. Write a sentence about what feels unseen. Which part of the answer speaks to it, being known by the Creator, receiving strength, or being able to keep walking?
Return to verses 29–31 when you have a real task to face. Ask for enough strength for the step you are taking. If you later see a way to support someone else who is weary, the movement from possessing strength to giving it has already been modeled for you.