The most common and most likely answer to this crossword clue is the 5 letter word KORAN
K
O
R
A
N
More clues leading to the result KORAN
- Holy text published on approval from the east
- Unanswerable Buddhist question about religious leader in Holy Book
- Puzzling question about right for sacred text
- A passage from Habakkuk or another sacred book
- With punchy ending, published good book
- Passage from paperback or another good book
- Asian missing Eastern holy book
- Managed to support return of good scriptures
- ...and men in Kansas getting holy book
- Fine revolutionary rushed to get sacred book
Buddy explains!

The straight part
We know that "sacred book" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sacred book = koran.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.