If thou bring them not a revelation they say: "Why hast thou not got it together?" Say: "I but follow what is revealed to me from my Lord: This is (nothing but) lights from your Lord and guidance and mercy for any who have faith." 1174 1175
"Ayat" here, I think, means specially an Ayat of the Holy Qur-an. The infidels did not believe in revelation, and used to taunt the Holy Prophet, as much as to say that he used to put together words and promulgate them as revelation. The answer is contained in the sentence that follows. No human composition could contain the beauty, power, and spiritual insight of the Qur-An. Without inspiration it is impossible to suppose that a man, with or without literary and philosophic training could produce such a book as the Qur-an. Commentators of the Qur-An, however, consider Ayah here to refer to miracle as the context seems to evidence.
"Lights": eyes, faculty of spiritual insight. The revelation is for us (1) spiritual eyes, (2) guidance, and (3) mercy, (1) is the highest in degree: just as a blind man, if he is given eyes and the faculty of sight, is at once removed into an entirely new world, so those who can reach the stage of spiritual insight pass into and become citizens of a wholly new spiritual World, (2) is next in degree; the man of the world can act up to the teaching about right conduct and prepare for the Hereafter, (3) is the Mercy of Allah, free to every one, saint and sinner, who sincerely believes and puts his trust in Allah.