He it is Who has revealed to you this perfect Book, some of its verses are definite and decisive. They are the basic root (conveying the established meanings) of the Book (- Ummal Kitâb) and other (verses) are susceptible to various interpretations. As for those in whose hearts is perversity follow (verses) that are susceptible to different interpretations, seeking (to cause) dissension and seeking an interpretation (of their own choice). But no one knows its true interpretation except Allâh, and those who are firmly grounded in knowledge. They say, `We believe in it, it is all (- the basic and decisive verses as well as the allegorical ones) from our Lord.' And none takes heed except those endowed with pure and clear understanding.