Musannaf Ibn Abi Shaybah

Hazrat Nafi' says that Hazrat Ibn Umar (may Allah be pleased with them) disliked calling the Surahs of the Qur'an "Mufassal" and used to say: The entire Qur'an is mufassal and clear. But you should say: the short Surahs of the Qur'an.

Hazrat Salim narrates that Hazrat Ibn Umar (may Allah be pleased with them) said: Hazrat Umar asked me, "How much of the Qur'an have you memorized?" I replied, "One surah." Hazrat Abdullah says: Then he neither commanded us to do any work nor forbade us from any work except that he said: "So if you learn anything from the Qur'an, then these detailed surahs are obligatory upon you, because they are better preserved."

Hazrat Asim narrates that Hazrat Ibn Sirin said: Do not say: "a small surah," nor say: "a light surah." The narrator says: I asked, "Then how should I say?" He replied: Say like this! "An easy surah." Because Allah has said: "And indeed, We have made this Qur'an easy for remembrance, so is there anyone who will take heed?" And do not say: "a light surah," because Allah has said: "We are about to send down to you a weighty word."

Hazrat Asim says that Hazrat Abu Al-Aaliyah also mentioned a similar subject as before, but there is some difference in the wording.