Sunan Abi Dawud Book 5, Hadith 102
The Messenger of Allah (ﷺ) used to observe the witr prayer with nine rak'ahs. Then he used to pray seven rak'ahs (of witr prayer). He would pray two rak'ahs sitting after the witr in which he would recite the Qur'an (sitting). When he wished to bow, he stood up and bowed and prostrated.
Abu Dawud said: These two traditions have been transmitted by Khalid b. 'Abd Allah al-Wasiti. In his version he said: 'Alqamah b. Waqqas said: O mother, how did he pray the two rak'ahs ? He narrated the rest of the tradition to the same effect.
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.
Sa'd ibn Hisham said: I came to Medina and called upon Aisha, and said to her: Tell me about the prayer of the Messenger of Allah (ﷺ).
She said: The Messenger of Allah (ﷺ) used to lead the people in the night prayer, and then go to his bed and sleep. When midnight came he got up, went to answer the call of nature and to perform ablution with water. Having performed ablution, he entered the mosque and prayed eight rak'ahs.
To my mind he performed the recitation of the Qur'an, bowing and prostrating equally. He then observed witr with one rak'ah and prayed two rak'ahs sitting. Then he lay down on the ground. Sometimes Bilal came to him and called him for prayer. He then dozed, and sometimes I doubted whether he dozed or not, till he (Bilal) called him for prayer.
This is the prayer he offered till he grew old or put on weight. She then mentioned how he put on weight as Allah wished.