Written authority giving protection for those eating Lebanese on vacation (5)
I believe the answer is:
bible
'written authority' is the definition.
'bible' can be an answer for 'authority' (bible can mean any important or authoritative text). I'm not certain of the 'written' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bible that I've seen before include "reliable work" , "Authoritative source" , "Holy Scripture" , "It contains scriptures" , "Christian holy book" .)