Musnad Ahmad 1153:648

Muhammad ibn Ja'far narrated to us, he said: Shu'bah narrated to us, from Abu Ishaq, he said: I heard 'Abd al-Rahman ibn Yazid narrating from al-Aswad, from 'Aishah, that she said: "The family of Muhammad, may Allah bless him and grant him peace, never ate their fill of barley bread for two consecutive days until the Messenger of Allah, may Allah bless him and grant him peace, was taken."