I read an interesting line in the shakespeare play Macbeth.
Lady macbeth has nightmares about the murder of king Duncan that she and her husband macbeth did.
She would sleepwalk and then be seen by her servants. She would look at her hands and dream that there were full of the kings blood.
She once said, "All the perfumes of Arabia will not sweeten this little hand." As she would fane washing them.
Act five scene one