Completely fascinated by Hebraic books, written from right to left (2,4)
I believe the answer is:
in toto
'completely' is the definition.
(thesaurus)
'fascinated by hebraic books written from right to left' is the wordplay.
'fascinated by' becomes 'into' (I've seen this before).
'hebraic books' becomes 'ot' (Old Testament).
'written from right to left' shows that the letters should be reversed in order.
'ot' backwards is 'to'.
'into'+'to'='IN TOTO'
(Other definitions for in toto that I've seen before include "As a whole (Lat.)" , "In entirety" , "As a whole (Latin)" , "All told" , "Tranquillity" .)