Musnad Ahmad 1153:1538

'Abd al-Rahman ibn Mahdi narrated to us, from Hammad ibn Zayd, from Marwan Abu Lubabah, who said: I heard 'Aishah say: The Messenger of Allah (peace and blessings of Allah be upon him) would fast until we would say, "He does not intend to break his fast," and he would break his fast until we would say, "He does not intend to fast." And he used to recite every night Bani Isra'il (Surah Al-Isra) and Az-Zumar.