Musnad Ahmad 30:2266

'Affan narrated to us, Hammad narrated to us, he said: Qays and Habib informed us, from 'Ata' ibn Abi Rabah, from Abu Hurayrah, that he said: "In every prayer, one recites. So, what the Messenger of Allah (peace and blessings of Allah be upon him) made us hear, we have made you hear; and what he kept hidden from us, we have kept hidden from you."