Isaiah 40:28-31 American Standard Version (ASV)

28. Hast thou not known? hast thou not heard? The everlasting God, Jehovah, the Creator of the ends of the earth, fainteth not, neither is weary; there is no searching of his understanding.

29. He giveth power to the faint; and to him that hath no might he increaseth strength.

30. Even the youths shall faint and be weary, and the young men shall utterly fall:

31. but they that wait for Jehovah shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; they shall walk, and not faint.

Isaiah 40