Isaiah 40:9-10, 28-31 New International Version (NIV)

You who bring good news to Zion,
go up on a high mountain.
You who bring good news to Jerusalem,
lift up your voice with a shout,
lift it up, do not be afraid;
say to the towns of Judah,
“Here is your God!”
See, the Sovereign Lord comes with power,
and he rules with a mighty arm.
See, his reward is with him,
and his recompense accompanies him.

Do you not know?
Have you not heard?
The Lord is the everlasting God,
the Creator of the ends of the earth.
He will not grow tired or weary,
and his understanding no one can fathom.
He gives strength to the weary
and increases the power of the weak.
Even youths grow tired and weary,
and young men stumble and fall;
but those who hope in the Lord
will renew their strength.
They will soar on wings like eagles;
they will run and not grow weary,
they will walk and not be faint.