45
The arguments contained in v. 37 may be elaborated like this:
(1) The Qur'an confirms that which had been revealed before and presents the same fundamental principles and teachings which were taught by the Prophets who came before Muhammad (Allah's peace be upon him). Had he invented the Qur'an, he would have made additions to the truths of the former books in order to make himself conspicuous.
(2) The Qur'an explains in detail and amplifies the fundamental principles and teachings contained in "the Book", that is, the Scriptures brought by the former Prophets, and adds more evidence and explanations to it so that it may be better understood and practiced.