Holy book of Islam (5)
I believe the answer is:
koran
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">holy book of islam</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for koran that I've seen before include "Sacred writings of Islam" , "Sacred book of Islam (5)" , "Good book" , "Islam's sacred book" , "words to prophet" .)