Full Idea
Some of the verses of the Koran are precise in meaning - they are the foundations of the Book - and others are ambiguous. Disbelievers follow the ambiguous part, to create dissension by seeking to explain it. No one knows its meaning except Allah.
Gist of Idea
Unbelievers try to interpret the ambiguous parts of the Koran, simply to create dissension
Source
Mohammed (The Koran [c.622], Ch.3)
Book Reference
Mohammed: 'The Koran', ed/tr. Dawood,N.J. [Penguin 1968], p.397
A Reaction
It is tempting to ask why some of the verses are ambiguous. The implication here is that they are a deliberate test for believers, like the apple in the garden of Eden.