Isaiah 40:31 says: 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.
(KJV).
The verse closes Isaiah 40, a chapter that describes the greatness of God and the renewal of those who wait on him. Read it in context at Isaiah 40:31, or the full chapter at Isaiah 40.