Aisha said, "I never saw the Messenger of Allah ﷺ pray his voluntary prayers sitting down until a year before his death. After that, he would pray his voluntary prayers sitting down, and he would recite the surah slowly and measuredly, until it became longer than one even longer than it."
ﷺ قالت: ما رأيت رسول الله ﷺ صلى شبحته قاعدا قط حتى كان قبل وفاته بعام، فكان يصلي في سبحته قاعدا، ويقرأ بالسورة فيرتلها، حتى تكون أطول من أطول منها.
Malik narrated it in Salat al-Jamaah (21) from Ibn Shihab, from Saaib bin Yazid, from Muttalib bin Abu Wada, Sahmi, from Hafsa, mentioning it as such. Muslim also narrated it in Salat al-Musafirin (733) through the route of Malik, in like manner.