Musnad Ahmad 1153:2302

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, who said: Shu'bah ibn al-Hajjaj narrated to me, from Sa'd ibn Ibrahim, from Talhah ibn 'Abdullah ibn 'Uthman ibn 'Ubaydullah ibn Ma'mar, who said: I heard 'Aishah say: The Messenger of Allah, peace and blessings of Allah be upon him, leaned toward me to kiss me. She said: So I said to him: "O Messenger of Allah, I am fasting." She said: The Messenger of Allah, peace and blessings of Allah be upon him, said to me: "And I am fasting." Then he kissed me.