Summary of oriental holy book (7)
I believe the answer is:
epitome
'summary' is the definition.
(epitome is a kind of summary)
'oriental holy book' is the wordplay.
'oriental' becomes 'e'.
'holy' becomes 'pi' (I've seen this in other clues).
'book' becomes 'tome' (tome is a kind of book).
'e'+'pi'+'tome'='EPITOME'
'of' acts as a link.
(Other definitions for epitome that I've seen before include "Essence or embodiment" , "Personification" , "ie Tempo (anag.)" , "Summary; embodiment" , "Embodiment or perfect example" .)