those who believe say why has a surah not been sent down? but when a precise surah is revealed and fighting is mentioned therein you see those in whose hearts is hypocrisy looking at you with a look of one overcome by death. and more appropriate for them 
ويقول الذين آمنوا لولا نزلت سورة فإذا أنزلت سورة محكمة وذكر فيها القتال رأيت الذين في قلوبهم مرض ينظرون إليك نظر المغشي عليه من الموت فأولى لهم