Spot remover's first for prophet (4)
I believe the answer is:
seer
'for prophet' is the definition.
(both can mean someone who tells the future)
'spot remover's first' is the wordplay.
'spot' becomes 'see' (both can mean to notice or observe).
'remover's first' becomes 'r' (1st letter of 'remover').
'see'+'r'='SEER'
(Other definitions for seer that I've seen before include "Oracle or prophet" , "Regard with respect" , "One who knows the future" , "One has unusual foresight" , "Distinguishing quality" .)