Isaiah 40: 28-31

Did you not know? Had you not heard? Yahweh is the everlasting God, he created the remotest parts of the earth. He does not grow tired or weary, his understanding is beyond fathoming. He gives strength to the weary, he strengthens the powerless. Youths grow tired and weary, the young stumble and fall, but those who hope in Yahweh will regain their strength, they will sprout wings like eagles, though they run they will not grow weary, though they walk they will never tire. --Isaiah 40:28-31