Narrated Zirr bin Hubaish
I asked Ubai bin Ka`b regarding the two Muwwidhat (Surats of taking refuge with Allah). He said, "I asked the Prophet (ﷺ) about them, He said, 'These two Surats have been recited to me and I have recited them (and are present in the Qur'an).' So, we say as Allah's Messenger (ﷺ) said (i.e., they are part of the Qur'an."