What is the significance of sleep in Macbeth?
In Macbeth, sleep symbolizes clear conscience, peace, and innocence. Sleep is vital when it comes to good health and well-being of characters. Sleep is a significant symbol in the play because it tells us more about the inner state of characters. When Macbeth kills king Duncan, he is aware of the fact that he will never be able to enjoy the benefits of clear conscience and inner stability like he used to:
Methought I heard a voice cry 'Sleep no more!
Macbeth does murder sleep', the innocent sleep,
Sleep that knits up the ravell'd sleeve of care,
The death of each day's life, sore labour's bath,
Balm of hurt minds, great nature's second course,
Chief nourisher in life's feast...
He voluntarily deprives himself of the opportunity to lead a healthy and normal life. Now that he "does murder sleep," he will have to deal with hallucinations and visions which are the results of his guilt-ridden conscience.
Lady Macbeth's lack of good sleep and her episodes of sleepwalking and hallucinations suggest that when one gets involved in corruption and abnormality, one must suffer. She suffers because her peace of mind is taken away from her forever. In fact, she took it away when she manipulated her husband into murdering king Duncan.
So, sleep, as a symbol, serves as a reminder that both Macbeth and Lady Macbeth have irrevocably stepped into the realm of darkness and corruption. The play shows us that they soon lose their stability and peace, so their deaths are inevitable.