Abdallah b. Mas'ud said,“I know the comparable suras which the Prophet used to join together; ”and he mentioned twenty suras at the beginning of al-Mufassal,1 according to Ibn Mas'ud’s arrangement, two in a rak'a, the last of them being H. M. ad-Dukhan,2 and“About what do they ask one another?”3 1. A title given to the suras from 49 to the end, but several other suras are also mentioned:37, 45, 47, 48, 50, 61, 67, 87, and 93. The name is most appropriately explained ay meaning that this is the section of the Qur’an which contains many shorter suras. 2. Al-Qur’an; 94. As this is included as one of the suras in al Mufassal, it suggests that this section begins earlier than the first number mentioned in the note referred to above. 3. Al-Qur'an; 78. (Bukhari and Muslim.)