Musnad Ahmad 1153:260

Yahya narrated to us, Sa'id ibn Abi 'Aruba narrated to us, from Qatadah, from Zurarah ibn Awfa, from Sa'd ibn Hisham, that he divorced his wife, then traveled to Medina to sell property he had there and invest it in weapons and horses, then fight the Romans until he died. He met a group of his people, and they told him that a group of six of his people had intended to do that during the time of the Messenger of Allah (peace and blessings of Allah be upon him), and he said: "Do you not have a good example in me?" So he forbade them from that. He made them witnesses to his taking her back, then he returned to us and informed us that he went to Ibn Abbas and asked him about the Witr. He said: "Shall I not inform you of the most knowledgeable person on earth regarding the Witr of the Messenger of Allah (peace and blessings of Allah be upon him)?" He said: "Yes." He said: "Go to Aisha and ask her, then return to me and inform me of her reply to you." He said: "I went to Hakim ibn Aflah and asked him to accompany me to her. He said: 'I will not go near her, for I forbade her from saying anything about these two factions, but she refused and persisted in them.' I adjured him, so he came with me. We entered upon her, and she said: 'Hakim?' She recognized him. He said: 'Yes.' She said: 'Who is this with you?' He said: 'Sa'd ibn Hisham.' She said: 'Which Hisham?' He said: 'Ibn 'Amir.' She prayed for mercy upon him and said: 'Amir was a good man.' I said: 'O Mother of the Believers, inform me about the character of the Messenger of Allah (peace and blessings of Allah be upon him).' She said: 'Do you not read the Quran?' I said: 'Yes.' She said: 'The character of the Messenger of Allah (peace and blessings of Allah be upon him) was the Quran.'" I intended to stand up, then it occurred to me to ask about the night prayer (Qiyam) of the Messenger of Allah (peace and blessings of Allah be upon him). I said: "O Mother of the Believers, inform me about the night prayer of the Messenger of Allah (peace and blessings of Allah be upon him)." She said: "Do you not read this Surah: 'O you who are wrapped in garments' (Al-Muzzammil)?" I said: "Yes." She said: "Allah, the Mighty and Majestic, made the night prayer obligatory at the beginning of this Surah. The Messenger of Allah (peace and blessings of Allah be upon him) and his companions stood for a year until their feet swelled. Allah, the Mighty and Majestic, withheld the end of it in the heaven for twelve months, then Allah, the Mighty and Majestic, sent down the alleviation at the end of this Surah. So the night prayer of the Messenger of Allah (peace and blessings of Allah be upon him) became voluntary after it had been obligatory." I intended to stand up, then it occurred to me to ask about the Witr of the Messenger of Allah (peace and blessings of Allah be upon him). I said: "O Mother of the Believers, inform me about the Witr of the Messenger of Allah (peace and blessings of Allah be upon him)." She said: "We used to prepare his toothstick (siwak) and his water for purification for him. Allah, the Mighty and Majestic, would awaken him whenever He willed to awaken him at night. He would use the toothstick, then perform ablution, then pray eight rak'ahs. He would not sit in them except at the eighth; he would sit, remember his Lord, the Mighty and Majestic, supplicate, and seek forgiveness. Then he would rise without saying the taslim. Then he would pray the ninth, then sit, praise his Lord, remember Him, and supplicate. Then he would say the taslim in a way that we could hear. Then he would pray two rak'ahs while sitting after he had said the taslim. That is eleven rak'ahs, my son." "When the Messenger of Allah (peace and blessings of Allah be upon him) grew old and put on weight, he prayed Witr with seven, then prayed two rak'ahs while sitting after he had said the taslim. That is nine, my son." "The Prophet of Allah (peace and blessings of Allah be upon him), when he performed a prayer, liked to be consistent in it. If sleep, pain, or illness kept him from the night prayer, he would pray twelve rak'ahs during the day. I do not know that the Prophet of Allah (peace and blessings of Allah be upon him) ever recited the entire Quran in one night, nor did he pray all night until morning, nor did he fast a full month other than Ramadan." I went to Ibn Abbas and told him her report. He said: "She spoke the truth. If I were not in the habit of visiting her, I would have gone to her until I heard it directly from her."