When you (O Messenger) do not produce for them a sign (a miracle of the kind they desire, or Revelation temporarily ceases), they say, "Were you unable to make one up?" Say: "I only follow whatever is revealed to me from my Lord. This (the Qur’an) is the light of discernment and insight (into the truth) from your Lord, and guidance and mercy for people who will believe and who have already believed."