Musnad Ahmad 1153:416

'Abd al-Samad narrated to us, Shu'bah narrated to us, he said: Ibn Abi al-Safar narrated to us, from al-Sha'bi, from 'Abd al-Rahman ibn al-Harith, from 'Aishah, she said: "He—meaning the Prophet, peace and blessings of Allah be upon him—would wake up in a state of janabah (major ritual impurity), then he would perform ghusl (ritual bath), then he would go out to the prayer, and I would hear his recitation, and he would fast."