Sahih Muslim 1704

A'isha reported: The Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) used to pray while sitting (when he grew old) and he recited in this position and when the recitation equal to thirty or forty verses was left, he would then stand up and recite..

A'isha reported: The Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) used to recite in sitting position (while observing the Tahajjud prayer) and when he intended to bow, he would stand up and recite (for the duration in which) a man (ordinarily)..

Alqama b. Waqqas reported: I asked 'A'isha how the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) did in the two rak'ahs as he (observed them) sitting. She said: He would recite (the Qur'an) in them, and when he intended to bow, he would stand up..

Abdullah b. Shaqiq reported: I asked 'A'isha whether the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) observed (Nafl) sitting. She said: Yes, when the people had made him old. ..

Abdullah b. Shaqiq reported: I said to 'A'isha and she made a mention of that (recorded above) about the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ). ..

A'isha reported that the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) died (in this very state) that he observed most of his (Nafl) prayers in a sitting position. ..