(Or lest you should say) and so that you will not say on the Day of Judgement: (If the Scripture had been revealed unto us) as it was revealed to the Jews and Christians, (we surely had been better guided than are they) we would be swifter in answering the Messenger and we would also have a sounder religion. (Now hath there come unto you a clear proof) a clarification (from your Lord) i.e. the Qur'an and the Messenger, (a guidance) from error (and a mercy) for the one who believes in him; (and who doeth greater wrong) who is more insolent and more daring vis-à-vis Allah (than he who denieth the revelations of Allah) who denies Muhammad (pbuh) and the Qur'an, (and turneth away from them? We award unto those who turn away from Our revelations) Muhammad (pbuh) and the Qur'an (an evil doom) a severe torment (because of their aversion) vis-à-vis Muhammad and the Qur'an.