The day shall come when We summon a witness from every nation, the Messenger who evolved from their midst and conveyed Our message, to testify of his peoples' response and We summon you O Muhammad to testify of your peoples' response. The Book -the Quran- which We sent down to you is the fountain-head of divine knowledge and the chief source of divine information. It illucidates every aspect of every thought and it is a guide into all truth and a mercy extended to the people and a joyful tidings to those who conformed to Islam.