have a clear conscience

have a clear conscience

To be guiltless or have no feelings of guilt or remorse over something. Don't you dare accuse me of causing this, I have a clear conscience! Some people think I should have treated him better, but I have a clear conscience in this whole affair.
See also: clear, conscience, have
Farlex Dictionary of Idioms.

have a clear conscience (about someone or something)

 and have a clean conscience (about someone or something)
to be free of guilt about someone or something. I'm sorry that John got the blame. I have a clean conscience about the whole affair. I have a clear conscience about John and his problems. I didn't do it. I swear to that with a clean conscience.
See also: clear, conscience, have
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

have a clear conscience

Also, have a clean conscience. Feel free of guilt or responsibility. For example, I have a clear conscience-I did all I could to help. This idiom is also put as one's conscience is clear or clean , as in His conscience is clean about telling the whole story. The adjective clear has been used in the sense of "innocent" since about 1400; clean was so used from about 1300.
See also: clear, conscience, have
The American Heritage® Dictionary of Idioms by Christine Ammer.

clear conscience, to have a

To feel free from blame, obligation, or a similar burden because one is guiltless (or so believes). The sixteenth-century writer John Lyly used the term several times in his Euphues (1580)—“a cleere conscience is a sure card”—and the same phrase turned up in James Howell’s proverb collection of 1659. Nearly a century later Benjamin Franklin wrote, “Keep Conscience clear, then never fear” (Poor Richard’s Almanack, 1749).
See also: clear, have
The Dictionary of Clichés by Christine Ammer
See also:
  • clear conscience, to have a
  • (one's) conscience is clear
  • have a clean conscience
  • have a clear conscience about (someone or something)
  • (one's) conscience is clean
  • have a clean conscience about (someone or something)
  • prick (one's) conscience
  • prick your conscience
  • don't you dare
  • don't you dare!