The eagle is mentioned more than any other bird in the Bible. It is able to look right into the sun, to soar higher and swifter than any other bird can fly.
The youth fall. Young men get weary and faint, and then they utterly fall. But not so with those who wait upon the Lord, because "they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles."
The concept of wings is interesting. Wings serve as protection for the baby chicks, and they enable the birds to fly and to soar up high. Oh, the beauty of wings! They have such power and such strength.
We can always have our strength renewed. Our life may slow down to a walk and we may no longer work, perhaps because we are sick and confined to bed. But when all of that is going on, God still has a plan and a provision. To "run" means that we can go full-speed ahead at whatever we do in life. To "walk," however, means that we can't do those things now, yet we go on with the integrity and the capacity God gives.
So if you are sick and laid up in a hospital, thank God for His mercy. You did run and did not get weary; but now you have slowed down to a walk, and you do not faint.