Proclamation of expert male spies on religious books from the east (14)

'proclamation' is the definition.
(thesaurus)

'expert male spies on religious books from the east' is the wordplay.
I cannot really see how this works, but
'expert' could be 'pro' (short for professional) and 'pro' is found in the answer.
'male' could be 'm' (common abbreviation) and 'm' is present in the answer.
'spies' could be 'cia' (Central Intelligence Agency) and 'cia' is found in the answer.
'on' could be 'to' and 'to' is found in the answer.
'religious' could be 'nun' (nun is a kind of religious) and 'nun' is found in the answer.
'east' could be 'e' (abbreviation) and 'e' is found in the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).

'of' is the link.

Can you help me to learn more?