Zuhri reported this hadith with the same chain of transmitters, except this that he made a mention of one year or two years.
Sahih Muslim Book 6, Hadith 143
← Previous Hadith Never did I see the Messenger of Allah (ﷺ) observing supererogatory prayer sitting till one year before his death when he would observe Nafl prayer in a sitting position, and he would recite the Surah (of the Qur'an) in such a slow-measured tone (that duration of its recital) became more lengthy than the one longer than this.

Sahih Muslim Book 6, Hadith 142 Next Hadith → Jabir b. Samura reported that the Messenger of Allah (ﷺ) observed (Nafl) prayer sitting before his death.

Sahih Muslim Book 6, Hadith 144