Virtues of the Qur'an

Bukhari :: Book 6 :: Volume 61 :: Hadith 554

Narrated Said bid Jubair:

Those Suras which you people call the Mufassal, are the Muhkam. And Ibn 'Abbas said, "Allah's Apostle died when I was a boy of ten years, and I had learnt the Muhkam (of the Qur'an).