Source of wisdom, a prophet (6)
I believe the answer is:
oracle
This clue is a double definition.
'source of wisdom' is the first definition.
(I've seen this in another clue)
'a prophet' is the second definition.
(I know that prophet can be written as oracle)
(Other definitions for oracle that I've seen before include "Prophet or sage" , "source of revelation?" , "Ancient Greek expounder of wisdom" , "sign of things to come" , "She prophesised" .)