Surat Al Hijr (5-6)

{مَّا تَسْبِقُ مِنْ أُمَّةٍ أَجَلَهَا وَمَا يَسْتَأْخِرُونَ} (الحجر : 5 )

5- The time of destruction of a nation shall not be delayed from its prescribed time, but shall come to them in the destined place and time.

{وَقَالُواْ يَا أَيُّهَا الَّذِي نُزِّلَ عَلَيْهِ الذِّكْرُ إِنَّكَ لَمَجْنُونٌ} (الحجر : 6 )

6- The polytheists of Makkah said to the Messenger of Allah (peace be upon him): O you who claims that the Qur'an comes down to him. You are crazy by your claim.