Virtues of the Qur'an

Bukhari :: Book 6 :: Volume 61 :: Hadith 555

Narrated Said bin Jubair:

Ibn 'Abbas said, "I have learnt all the Muhkam Suras during the life time of Allah's Apostle." I said to him, 'What is meant by the Muhkam?" He replied, "The Mufassal."