Mishkat al-Masabih 1257
Sa‘d b. Hisham said:
I went to ‘A’isha and said, “Mother of the faithful, tell me about the nature of God’s Messenger.” She asked, “Do you not recite the Qur’an?” On my replying that I certainly did, she said, “The Prophet’s nature was the Qur’an.”* I said, “Mother of the faithful, tell me about the witr of God’s Messenger.” She replied, “I used to prepare his toothstick and his water for ablution, and God would rouse him to the extent He wished during the night. He would use the toothstick, perform ablution, and pray nine rak'as , sitting only during the eighth of them, then he would make mention of God, praise and supplicate Him, then he would get up without uttering the salutation and pray the ninth. After that he would sit, make mention of God, praise and supplicate Him, then utter a salutation loud enough for me to hear. He would then pray two rak'as sitting after uttering the salutation, and that made eleven rak'as , sonny. But when God’s Messenger grew old and became fleshy he observed a witr of seven, doing in the two rak'as , as he had done formerly, and that made nine, sonny. When God’s prophet prayed a prayer he liked to keep on observing it, but when sleep or pain made it impossible for him to get up during the night; he prayed twelve rak'as during the day. I am not aware of God’s prophet having recited the whole Qur’an in a night, or praying through a whole night till morning, or fasting a complete month, except Ramadan.” 

*i.e. the good characteristics included in the Qur’an were shown by the Prophet in his own life.

Muslim transmitted it.
وَعَن سعد بن هِشَام قَالَ انْطَلَقْتُ إِلَى عَائِشَةَ فَقُلْتُ يَا أُمَّ الْمُؤْمِنِينَ أَنْبِئِينِي عَنْ خُلُقِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَتْ: أَلَسْتَ تَقْرَأُ الْقُرْآنَ؟ قُلْتُ: بَلَى. قَالَتْ: فَإِنَّ خُلُقَ نَبِيِّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ الْقُرْآنَ. قُلْتُ: يَا أُمَّ الْمُؤْمِنِينَ أَنْبِئِينِي عَنْ وَتْرِ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَتْ: كُنَّا نُعِدُّ لَهُ سِوَاكَهُ وَطَهُورَهُ فَيَبْعَثُهُ اللَّهُ مَا شَاءَ أَنْ يَبْعَثَهُ مِنَ اللَّيْلِ فَيَتَسَوَّكُ وَيَتَوَضَّأُ وَيُصَلِّي تِسْعَ رَكَعَاتٍ لَا يَجْلِسُ فِيهَا إِلَّا فِي الثَّامِنَةِ فَيَذْكُرُ اللَّهَ وَيَحْمَدُهُ وَيَدْعُوهُ ثُمَّ يَنْهَضُ وَلَا يُسَلِّمُ فَيُصَلِّي التَّاسِعَةَ ثُمَّ يَقْعُدُ فَيَذْكُرُ اللَّهَ وَيَحْمَدُهُ وَيَدْعُوهُ ثُمَّ يُسَلِّمُ تَسْلِيمًا يُسْمِعُنَا ثُمَّ يُصَلِّي رَكْعَتَيْنِ بَعْدَمَا يُسَلِّمُ وَهُوَ قَاعد فَتلك إِحْدَى عشرَة رَكْعَة يابني فَلَمَّا أَسَنَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَأَخَذَ اللَّحْمَ أَوْتَرَ بِسَبْعٍ وَصَنَعَ فِي الرَّكْعَتَيْنِ مِثْلَ صَنِيعِهِ فِي الْأُولَى فَتِلْكَ تِسْعٌ يَا بُنَيَّ وَكَانَ نَبِيُّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا صَلَّى صَلَاةً أَحَبَّ أَنْ يُدَاوِمَ عَلَيْهَا وَكَانَ إِذَا غَلَبَهُ نَوْمٌ أَوْ وَجَعٌ عَنْ قِيَامِ اللَّيْلِ صَلَّى مِنَ النَّهَارِ ثِنْتَيْ عَشْرَةَ رَكْعَةً وَلَا أَعْلَمُ نَبِيَّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَرَأَ الْقُرْآنَ كُلَّهُ فِي لَيْلَةٍ وَلَا صَلَّى لَيْلَةً إِلَى الصُّبْحِ وَلَا صَامَ شهرا كَامِلا غير رَمَضَان. رَوَاهُ مُسلم