What Happens When You Go To Sleep?

[Aladin Azra]

A word sebt سَبْت (Sabbat) means "retrospection" not "rest". Benu Isra'il had a task to observe it and to remember what happened in Musa and pharaoh event, so they can remember how Allah helped them. There's a word subaat سُبَات also, used twice in the Qur'an with newm نَوْم (sleep), which is connected with "retrospective memory".

The beneficial effect of sleep on memory for past events (retrospective memory) has been thoroughly investigated and firmly established

Other then a physical rest, I think that sleeping and dreaming are needed to us for memory, both retrospective and prospective. There're a lot of scientific articles on this.

[Jafar]

Although this is an 'old thread' yet it's an interesting and important question.

If the question is: What happened to the consciousness when the body fell to sleep (or disabled such as in physical death)?
Then this diagram might provide a map towards an answer.



The explanation of it:
https://youtu.be/J7KweY07emc

I have read somewhere that when we go to sleep, our soul, our POV consciousness, goes to higher planes, thereby allowing the body to rest and heal itself, I believe that dreaming occurs in middle-higher planes, whilst deep dreamless sleep occurs in the highest plane.

Concur, it depends on the 'state' of the consciousness.
That's the reason why everything that you do, think, feel will have an impact towards your own soul.
"Whoso doeth right, it is for his soul, and whoso doeth wrong, it is against it." (45:15)

Or in shorter term: what goes around comes around.