Musnad Ahmad 30:2583

Waki’ narrated to us, he said: Ibn Abi Layla narrated to us, from ‘Ata’, from Abu Hurayrah, who said: "The Messenger of Allah, peace and blessings of Allah be upon him, used to lead us in prayer, so he would recite aloud and he would recite silently. So we recited aloud in what he recited aloud, and we recited silently in what he recited silently." And I heard him say: "There is no prayer except with recitation."