leave someone in peace
Avoid disturbing or bothering someone, as in It's best to leave Dean in peace when he's paying the bills. This expression uses peace in the sense of “undisturbed,” a usage dating from the early 1200s. Also see leave one alone; let be.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.