Prophet’s artistic grandma (5)
I believe the answer is:
moses
I believe this is a double definition.
'prophet's' is the first definition.
(Moses is an example)
'artistic grandma' is the second definition.
(US painter 'Grandma Moses')
(Other definitions for moses that I've seen before include "Lawmaker" , "Grandma - - , painter" , "Prophet of the Old Testament" , "one found in bulrushes, too" , "He led the Jews from slavery in Egypt" .)