'A'isha reported: The Messenger of Allah ( صلی اللہ علیہ وسلم ) fell ill and some of his Companions came to inquire after his health. The Messenger of Allah ( صلی اللہ علیہ وسلم ) (may peace he upon him) said prayer sitting, while (his Companions) said it (behind him) standing. He (the Holy Prophet) directed them by his gesture to sit down, and they sat down (in prayer). After finishing the (prayer) he (the Holy Prophet) said: The Imam is appointed so that be should be followed, so bow down when he bows down, and rise up when he rises up and say (prayer) sitting when he (the Imam) says (it) sitting. ________

This hadith is narrated with the same chain of transmitters by Hisham bin 'Urwa.