Those who believe say : " Why is not a Surah ( chapter of the Quran ) sent down ( for us ) ? But when a decisive Surah ( explaining and ordering things ) is sent down , and fighting ( Jihad - holy fighting in Allah 's Cause ) is mentioned ( i.e. ordained ) therein , you will see those in whose hearts is a disease ( of hypocrisy ) looking at you with a look of one fainting to death .