Egypt, say, employing books in hieroglyphics? (8)
I believe the answer is:
notation
'hieroglyphics?' is the definition.
(type of writing)
'egypt say employing books' is the wordplay.
'egypt say' becomes 'nation' (Egypt is a country).
'employing' indicates putting letters inside.
'books' becomes 'OT' (Old Testament).
'nation' enclosing 'ot' is 'NOTATION'.
'in' acts as a link.
(Other definitions for notation that I've seen before include "System of signs or symbols" , "An added comment or instruction" , "Set of representative symbols" , "System of musical symbols" , "Written comment" .)