Musnad Ahmad 1153:1904

Abu Mu'awiyah narrated to us, Al-A'mash narrated to us, from 'Umarah ibn 'Umayr, from Abu Bakr ibn 'Abd al-Rahman ibn al-Harith ibn Hisham, from 'Aishah, she said: The Messenger of Allah (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), and complete his fast.