It is He Who has revealed the Book to you. Some of its verses are absolutely clear and lucid, and these are the core of the Book. Others are ambiguous. Those in whose hearts there is perversity, always go about the part which is ambiguous, seeking mischief and seeking to arrive at its meaning arbitrarily, although none knows their true meaning except Allah. On the contrary, those firmly rooted in knowledge say: 'We believe in it; it is all from our Lord alone.' No one derives true admonition from anything except the men of understanding.