Rest a little while in early September (5)
I believe the answer is:
sleep
'rest' is the definition.
(I know that rest can be written as sleep)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for sleep that I've seen before include "Shut-eye" , "Be dormant" , "Slumber" , "crash" , "Natural state of unconscious rest" .)