Musannaf Ibn Abi Shaybah 32092 — Those who disliked saying

Salim said: Sayyiduna Ibn Umar (may Allah be pleased with them both) said: Sayyiduna Umar (may Allah be pleased with him) asked me: "How much of the Qur'an do you have memorized?" I said: "Ten surahs." He said to Ubaydullah bin Umar: "How much of the Qur'an do you have memorized?" He said: "One surah." Sayyiduna Abdullah said: He neither commanded us to do anything nor forbade us from anything, except that he said: "If you learn anything of the Qur'an, then hold to these Mufassal surahs, for they are better retained."