Musnad Ahmad 1153:2200

'Affan narrated to us, he said: Hammam narrated to us, Qatadah narrated to us, from Zurarah ibn Awfa, that Sa'd ibn Hisham narrated to him, from 'Aishah, he heard it from her, she said: "When the Prophet, peace and blessings of Allah be upon him, would miss his night prayer—due to his eyes overcoming him with sleep, or pain—he would pray twelve rak'ahs during the day."