He it is Who has revealed the Book to you ; some of its verses are decisive , they are the basis of the Book , and others are allegorical ; then as for those in whose hearts there is perversity they follow the part of it which is allegorical , seeking to mislead and seeking to give it ( their own ) interpretation. but none knows its interpretation except Allah , and those who are firmly rooted in knowledge say : We believe in it , it is all from our Lord ; and none do mind except those having understanding .