Musnad Ahmad 1153:1889

Muhammad ibn Salamah narrated to us, from Hisham, from Muhammad ibn Sirin, from Abdullah ibn Shaqiq, who said: I asked Aisha about the prayer of the Messenger of Allah, peace and blessings of Allah be upon him. She said: "He used to prolong the prayer while standing and while sitting. When he prayed standing, he would bow while standing, and when he prayed sitting, he would bow while sitting." And I asked her about the fasting of the Messenger of Allah, peace and blessings of Allah be upon him. She said: "The Messenger of Allah, peace and blessings of Allah be upon him, would fast until we would say: 'He has fasted, he has fasted, he has fasted,' and he would break his fast until we would say: 'He has broken his fast, he has broken his fast, he has broken his fast.' And he did not fast a complete month since he came to Medina, except for the month of Ramadan."