AC 3540 - What makes a book of the genuine Word?

AC 3540 [4]
That the book of Job is a book of the Ancient Church
is evident as before said
from its representative and significative style;
but it is not of those books
which are called the Law and the Prophets,
because it has not an internal sense
which treats solely of the Lord and of His kingdom;
for this is the one thing
that makes a book of the genuine Word.