Sleep is not a metaphor on its own, but once you put it in a sentence, such as: 'His resting place, the field, with a blanket of stars, as he drifted off into his everlasting sleep', it is a very powerful metaphor representing either death or peace.
Sleep is sometimes used as a metaphor for death
"I am chasing sleep" uses a metaphor.
The metaphor in "what storm then shook the ocean of my sleep" compares the disturbance in the speaker's sleep to the powerful and tumultuous force of a storm on the ocean, suggesting the intensity and disruption caused by whatever affected their slumber.
In the jungle the mighty jungle the lions sleep tonight,
To need some sleep - to spend some time with eyes shut
Thoreau uses the idea of sleep as a metaphor for the need to simplify and declutter one's life in order to live deliberately and authentically. He suggests that a clear mind and a simplified lifestyle can lead to a more meaningful existence, just as restful sleep rejuvenates the body.
No, "hit the hay" is an idiom that means to go to bed or go to sleep. It is not a metaphor, as it is a commonly used phrase with a specific meaning that is understood by native English speakers.
Its a metaphor
When Charley says he's a man now, then he gets rocked to sleep by the movement of the train. Getting rocked to sleep like a baby. That symbolizes that he's still a "baby" in the war.
In "Warriors: Sunrise," a metaphor could be something like "The warrior's heart was a blazing fire, fueled by his determination and courage as he faced his enemies." This metaphor compares the warrior's inner strength and resolve to a powerful, unstoppable force like fire.
It is a metaphor.
it is neither, it is personification
A hyperbole: A figure of speech in which exaggeration is used for emphasis or effect, as in I could sleep for a year or This book weighs a ton.