the sleep of the just
sleep the sleep of the just
To sleep easily and deeply, untroubled by one's conscience or satisfied with one's efforts. It was such manipulations of religious text to serve their purposes that they were able to commit such atrocities and sleep the sleep of the just. The team's captain will be sleeping the sleep of the just tonight after such a mighty and impressive performance this afternoon.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
the sleep of the justa deep, untroubled sleep.
The idea here is that only those with clear consciences can expect to have a peaceful night's sleep.
Farlex Partner Idioms Dictionary © Farlex 2017