Our Daily Bread (Deuteronomy 8:3)

It is easy to think that the Lord may in the best case scenario provide our food, but we need to be assertive to secure additional physical blessings.  It is tempting to think that the Lord takes care of the spiritual blessings, but we better get busy to secure the physical blessings.  However, our Lord commands us to pray that our Lord would provide our daily bread.  Why our daily bread?  What does daily bread have to do with physical blessings?  How does our request for our daily bread challenge us to see the bigger picture of God's provision?