Work, as we usually think of it, is energy expended for a further end in view; play is energy expended for its own sake, as with children's play, or as manifestation of the end or goal of work, as in "playing" chess or the piano. Play in this sense, then, is the fulfillment of work, the exhibition of what the work has been done for.
The Great Code: The Bible and Literature (ed. University of Toronto Press, 2006) - ISBN: 9780802091208