Musannaf Ibn Abi Shayba 3:3356

Hushaym and Ibn Idris narrated to us, from Ash'ath, from Kardus, from Abdullah, that al-Walid ibn Uqbah sent to him and said: "He should recite the Mother of the Book (al-Fatiha) and a surah from the Mufassal." Hushaym added in it: "Not from its short ones, nor from its long ones."