Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
muslim:738c[Chain 1] Zuhayr b. Ḥarb > Ḥusayn b. Muḥammad > Shaybān > Yaḥyá > Abū Salamah [Chain 2] Yaḥyá b. Bishr al-Ḥarīrī > Muʿāwiyah / Ibn Salāam > Yaḥyá b. Abū Kathīr > Abū Salamah

Abu Salama reported that he asked 'A'isha about the prayer of the Messenger of Allah (may peace he upon him) (during the night). The rest of the hadith is the same but with this exception that he (the Holy Prophet) observed nine rak'ahs including Witr.  

مسلم:٧٣٨cوَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ حَدَّثَنَا حُسَيْنُ بْنُ مُحَمَّدٍ حَدَّثَنَا شَيْبَانُ عَنْ يَحْيَى قَالَ سَمِعْتُ أَبَا سَلَمَةَ ح وَحَدَّثَنِي يَحْيَى بْنُ بِشْرٍ الْحَرِيرِيُّ حَدَّثَنَا مُعَاوِيَةُ يَعْنِي ابْنَ سَلاَّمٍ عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ قَالَ أَخْبَرَنِي أَبُو سَلَمَةَ

أَنَّهُ سَأَلَ عَائِشَةَ عَنْ صَلاَةِ رَسُولِ اللَّهِ ﷺ بِمِثْلِهِ غَيْرَ أَنَّ فِي حَدِيثِهِمَا تِسْعَ رَكَعَاتٍ قَائِمًا يُوتِرُ مِنْهُنَّ