Have you not known? Have you not heard? The LORD is 1the everlasting God, the Creator of the ends of the earth. He does not faint or grow weary; 2his understanding is unsearchable.
References for Isaiah 40:28
He gives power to the faint, and to him who has no might he increases strength.
Even youths shall faint and be weary, and young men shall fall exhausted;
but 3they who wait for the LORD shall renew their strength; they shall mount up with wings 4like eagles; they shall run and not be weary; they shall walk and not faint.
References for Isaiah 40:31