Waiting Upon the Lord

This week, I have been working on Isaiah 40:31, "Yet those who wait upon the Lord will gain new strength; they will mount up with wings like eagles, they will run and not get tired, they will walk and not become weary." NASV
Perhaps I should say that this passage of Scripture has been working on me.  The idea of waiting upon the Lord conjures three different word pictures:
First, the winding of a cord into a rope.  One might say that while we wait upon the Lord, He prepares for us a lifeline.
Secondly, it is used of the wicked waiting to ambush the righteous in Psalms 56:6 and 119:95. 
Thirdly, it is a picture of a farmer who waits eagerly until the crops are ready to harvest.
Neither of these are simply sitting idly by and waiting upon the Lord.  But these pictures are of being busy while we wait.  It has been said that we should work as though everything depends upon us and pray as though everything depends upon Him.  It is never passive, but always active.
Those who wait upon the Lord will gain new strength.  It should be noted that this is not to renew or refresh one's old strength.  It is rather the exchanging of my old spent strength for the new refreshed strength that only the Lord himself can give.
Much is made about how the last portion of this verse moves from flying to running to walking.  To some, it seems that the progression is backwards.  However, it seems to me to be easier to live by faith when we are flying or running, but the real life challenge is to be able to walk by faith.  I have been in a few places in my life where it was obvious that I was flying or running and I could not help but to trust in the Lord with all my heart or else I would fall for sure.  However, walking sometimes can seem so simple that we think we can do it without him.  Beware that you do not try this alone.