Musnad Ahmad 928:8

Abdullah narrated to us, Muhammad ibn al-Husayn ibn Ashkab narrated to me, Muhammad ibn Abi Ubaydah ibn Ma'n narrated to us, my father narrated to us, from al-A'mash, from Abu Ishaq, from Abd al-Rahman ibn Yazid, who said: Abdullah used to scrape the two *Mu'awwidhatayn* (Surah al-Falaq and Surah an-Nas) from his copies of the Mushaf, and he would say: "They are not from the Book of Allah." Al-A'mash said: And Asim narrated to us, from Zirr, from Ubayy ibn Ka'b, who said: We asked the Messenger of Allah, peace and blessings of Allah be upon him, about them. He said: "It was said to me, so I said."