You searched for: “quieta non movere”
Quieta non movere.
Not to disturb quiet things.

Better translated as "Don't disturb things that are at peace"; and by extension: "Let sleeping dogs lie."

There are those now who say, "If it isn't broken, don't try to fix it." Then there are the slang-mongers who say, "If it ain't broke, don't fix it."

This entry is located in the following units: Latin Proverbs, Mottoes, Phrases, and Words: Group Q (page 3) mot-, moto-, -motile, -motility, -motorial, -motoric, -motive, -motored; mov- (page 7) quies-, -quiet-, -quit- (page 2)