Sunan Abi Dawud 1350
سنن أبي داود#1350SahihNarrated 'Aishah:The Messenger of Allah (ﷺ) used to pray thirteen rak'ahs during the night, observing the witr prayer with nine (or as she said). He used to pray two rak'ahs while sitting and pray two rak'ahs of the dawn prayer between the adhan and the iqamah
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniHasan Sahih
Muhammad Muhyi Al-Din Abdul HamidHasan Sahih
Shuaib Al ArnautHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 5:101