Isaiah 40:29-31
KJV29He giveth power to the faint; and to them that have no might he increaseth strength. 30Even the youths shall faint and be weary, and the young men shall utterly fall: 31But 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.
He gives power to the faint and increases the strength of the weak. Even youths grow tired and weary, and young men stumble and fall. But those who wait upon the LORD will renew their strength; they will mount up with wings like eagles; they will run and not grow weary, they will walk and not faint.
Also in NKJV · ESV What the early church said about Isaiah 40:29-31
How the early church read itNo early comment
How it is used today: Claimed as a personal promise that God is with me, so I need not be afraid: He will strengthen me, help me, and hold me up through whatever I face.
First spoken: God spoke this to Israel: "But you, Israel, are My servant, Jacob whom I have chosen, the descendants of Abraham My friend" (Isaiah 41:8). The nations around were afraid and making idols (41:5-7), and God promised that Israel's enemies "shall be as nothing" (41:11-12) as He brought His people back from exile.
The early Christians: We found no early Christian comment on this verse in our library.
Keep in mind: This was first a promise to Israel, God's chosen servant, as He brought them home from exile. It shows that God keeps His word and stands by His people, but it was not spoken as a promise that every reader will be kept from fear, harm or hardship.