高枕无忧
a good conscience is a soft pillow.
a quiet conscience sleeps in thunder.
eg：he relaxed as a good conscience is a soft pillow after he had paid the debt.
同义词：生平不做亏心事，半夜不怕鬼敲门 a clear conscience is a coat of mail.
反义词：坐立不安 sit on a bag of fleas.
