Up, Sluggard, and waste not life; in the grave will be sleeping enough.

Benjamin Franklin (1706-1790) American statesman, scientist, philosopher, aphorist

Poor Richard (1741 ed.)
    (Source)

Repeated (as "There will be enough sleeping in the Grave") in the preface (1757-07-07) to Poor Richard Improved (1758 ed.); the preface was also reprinted as The Way to Wealth.

Possibly borrowed from (or from a common source as) Fuller (1727).