Musnad Ahmad 1153:912

'Affan narrated to us, he said: Hammad—meaning Ibn Salamah—said: 'Abdullah ibn Abi Mulaykah informed me, he said: Al-Qasim ibn Muhammad narrated to me, from 'Aishah, that the Messenger of Allah (peace and blessings of Allah be upon him) recited this verse: "It is He who has sent down to you, [O Muhammad], the Book; in it are verses [that are] precise - they are the foundation of the Book - and others unspecific" [Al 'Imran: 7], up to: "As for those in whose hearts is deviation [from truth]." When he finished it, he said: "Allah, the Almighty and Majestic, has named them, so if you see them, then beware of them."