"Let sleeping dogs lie -- To let a matter or person which at the present is at rest stay at rest, rather than to create a disturbance by bringing the matter up again or arousing the person. Chaucer wrote this in just the reverse form -- 'It is nought good a slepyng hound to wake.' ('Troylus and Crisedye,' 1374) -- and it was still so recorded some two hundred years later by John Heywood ('A Dialogue Conteynyng Prouerbes and Epigrammes,' 1592), 'It is ill wakyng of a sleapyng dogge.' But by the time of Charles Dickens ('David Copperfield, 1850) it had been turned about into the order of today's usage." From "Heavens to Betsy!" by Charles Earle Funk (Harper & Row, New York, 1955).
telling you to leave things as they are
Let Sleeping Dogs... was created in 2005.
Let sleeping dogs lie means leave things as they are and do not stir up trouble.
Men Women and Dogs - 2001 Let Sleeping Dogs Lie 1-5 was released on: USA: 11 November 2001
Leave things as they are.
The Joker Blogs - 2008 Let Sleeping Dogs Lyle - 1.11 was released on: USA: 31 October 2009
No. Let sleeping dogs lie.
Road Rovers - 1996 Let Sleeping Dogs Lie 1-5 was released on: USA: 26 October 1996
No, the phrase "let sleeping dogs lie" is not attributed to William Pitt. It is an English idiom that means it's best not to disturb a situation as it may cause trouble or complications.
Robert Walpole
It means don't stir up trouble.
The phrase is "let sleeping dogs lie." It is the same as "if it isn't broken, don't fix it." These mean something to the effect of if something is serving its purpose, don't change it. If you wake up the sleeping dog, it might bite you. If you fix something that isn't broken, it might not work the same.