How we cite our quotes:
Ghost of Prince Edward
[To KING RICHARD III]
Let me sit heavy on thy soul to-morrow!
Think, how thou stab'dst me in my prime of youth
At Tewksbury: despair, therefore, and die! (5.5.1)
When a parade of ghosts visits Richard on the eve of his death and reminds him of his crimes, Shakespeare lets us know that Richard's past has literally come back to haunt him.
Methought the souls of all that I had murder'd
To-morrow's vengeance on the head of Richard. (5.5.5)
Just in case we didn't get it the first time, Shakespeare beats us over the head with the idea that Richard's past has caught up with him.
Clock striketh (Stage Direction, Act 5, Scene 6)
Seriously, Shakespeare – we get it! Richard's time on earth is coming to an end.