Sahih al-Bukhari 5658

'Urwa related that 'A'isha said, "Some people visited the Prophet, may Allah bless him and grant him peace, while he was ill. He led them in the prayer while sitting down and they started to pray standing. He indicated to them to sit down. When he had finished, he said, 'The Imam is only appointed to be followed. When he goes into ruku', go into ruku', and when he rises, rise. When he prays sitting down, you should pray sitting down.'" Abu 'Abdullah said that al-Humaydi said, "This hadith was abrogated because in the last that the Prophet, may Allah bless him and grant him peace, prayed, he prayed sitting while the people were standing behind him."