From the statements of his eminence Grand Ayatollah Mousavi Ardebili:
The Qur’an is a book which states the historical, moral and … issues, but it is not a moral book, it is not a scientific book, but it is a book for “guiding the people” from its own viewpoint. There is no objection in ambiguity in a scientific book, such as one may read the theory of Einstein several times, but because it needs a supreme mathematics, he does not understand its message. Or it is mentioned in the history that Avicenna studied the book “ma ba'd at-tabi'at” several times, but he did not understand anything. It is a specification for a scientific book, but Qur’an is for guiding the people and it is a guideline and proof for human beings until the Hereafter, How is it possible it has ambiguity and by what logic can be accepted that it is not understandable?
Allah, the Almighty was sent down the Qur’an in a clear Arabic language “بلسان عربی مبین” and for human reminding, He made the Qur’an easy to remember “ولقد یسرنا القرآن للذکر” to put it as their frontispiece so that they will be cautious “لعلکم تتقون” or so that they will be subject to divine mercy “لعلکم ترحمون”.
However, much of its meaning is hidden from researcher, and much more from the ordinary people.
Imam Ali (peace be upon him) said: “وان القرآن ظاهره انیق وباطنه عمیق ... لا تفنی عجائبه ولا تنقضی غرائبه” Indeed, The Qur’an has a nice appearance and deep inside … Its astonishing stories and hidden secrets will not end.
As we mentioned, the generality of the Qur’an is understandable for all people, with this exception that everyone can use it according to his understanding, knowledge and capacity.
Imam Ali said about the Book of Allah and the understanding of the People: "کتاب الله عزوجل علی اربعة أشیاء: علی العبارة والاشارة واللطائف والحقایق؛ فالعبارة للعوام، والإشارة للخواص، واللطائف للاولیاء والحقایق للانبیاء." The book of Allah is based on four things: Expressions and symbols (points) and delicacies and facts. Its expressions are for ordinary people and its symbols are for experts, and its delicacies are for religious leaders and facts are for the prophets.
Therefore, the understating of different people towards its verses is different and the secret and truth of the Qur’an are clear only for the Prophet (s.) and Ahlul Bait (a.), however, the public can use it according to their understanding, so we must refer to Ahlul Bait (a.) for understating of the truth of Qur’an, because they are commentators of knowledge and Sciences.
In the Light of Revelation, Vol. 1, p. 88 – 90