Musnad Ahmad 1044:1

Abdullah ibn al-Walid al-Adani narrated to us, Sufyan narrated to us, Khalid al-Hadhdha’ narrated to us, from Abu Qilabah, from Muhammad ibn Abi ‘Aishah, from a man among the companions of Muhammad, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Perhaps you recite while the Imam is reciting?" He said it three times. They said: "We do indeed do that." He said: "Do not do so, except that one of you should recite the Opening of the Book (al-Fatihah)."