What does sleep represent?

In the play, sleep symbolizes peace and tranquility. When Macbeth murders Duncan in his sleep, he disturbs not just Duncan's slumber but his own ability to find inner peace for the rest of the play. Macbeth is plagued with a restless sleep for the remainder of the performance. As such, Macbeth serves as a disruption to an otherwise peaceful and prosperous reign, especially considering how well-liked Duncan was as a ruler.