Sahih al-Bukhari 5658

Allah's Messenger (ﷺ) prayed in his house while sitting during his illness and the people prayed behind him standing and he pointed to them to sit down. When he had finished the prayer, he said, "The Imam is to be followed and so when he bows you should bow; and when he lifts his head you should also do the same."

Allah's Messenger (ﷺ) during his illness prayed in his house sitting, whereas some people followed him standing, but the Prophet (ﷺ) beckoned them to sit down. On completion of the prayer he said, "The Imam is to be followed. So, bow when he bows, and raise your head when he raises his head." (See Hadith No. 657 Vol 1 for taking the verdict).

the mother of the believers: Allah's Messenger (ﷺ) during his illness prayed at his house while sitting whereas some people prayed behind him standing. The Prophet (ﷺ) beckoned them to sit down. On completion of the prayer, he said, 'The Imam is to be followed: bow when he bows, raise up your heads (stand erect) when he raises his head and when he says, 'Sami`a l-lahu liman hamidah' (Allah heard those who sent praises to Him) say then 'Rabbana wa laka l-hamd' (O our Lord! All the praises are for You), and if he prays sitting then pray sitting."

Once Allah's Messenger (ﷺ) rode a horse and fell down and the right side (of his body) was injured. He offered one of the prayers while sitting and we also prayed behind him sitting. When he completed the prayer, he said, "The Imam is to be followed. Pray standing if he prays standing and bow when he bows; rise when he rises; and if he says, 'Sami`a l-lahu-liman hamidah, say then, 'Rabbana wa laka lhamd' and pray standing if he prays standing and pray sitting (all of you) if he prays sitting." Humaid said: The saying of the Prophet (ﷺ) "Pray sitting, if he (Imam) prays sitting" was said in his former illness (during his early life) but the Prophet (ﷺ) prayed sitting afterwards (in the last illness) and the people were praying standing behind him and the Prophet (ﷺ) did not order them to sit. We should follow the latest actions of the Prophet.

The Messenger of Allah (ﷺ) fell ill and some of his Companions came to inquire after his health. The Messenger of Allah (ﷺ) said prayer sitting, while (his Companions) said it (behind him) standing. He (the Prophet) directed them by his gesture to sit down, and they sat down (in prayer). After finishing the (prayer) he (the Prophet) said: The Imam is appointed so that he should be followed, so bow down when he bows down, and rise upp when he rises up and say (prayer) sitting when he (the Imam) says (it) sitting.

Yahya related to me from Malik from Hisham ibn Urwa from his father that A'isha, the wife of the Prophet, (ﷺ), said, "The Messenger of Allah, (ﷺ), prayed while he was ill. He prayed sitting, and some people prayed behind him standing, and he indicated to them to sit down. When he left, he said, 'The imam is only appointed to be followed. When he goes into ruku, go into ruku and when he rises, rise and if he prays sitting, pray sitting .' "