Sunan Abi Dawud Book 2, Hadith 215
The IMAM is appointed only to be followed; so when he prays standing. Pray standing ; and when he raises himself, raise yourself: and when he prays sitting. Pray sitting.
The Prophet (ﷺ) said: The imam is appointed only to be followed. This version adds: When he recites (the Qur'an), keep silent."
Abu Dawud said: The addition of the words "When he recites, keep silent" in this version are not guarded. The misunderstanding, according to us, is on the part of Abu Khalid (a narrator).
when the prophet (ﷺ) became seriously ill, we prayed behind him while he was sitting and Abu Bakr was calling “Allah is most great “ to cause the people to hear the TAKBIR. Then he (the narrators) narrated the rest of the tradition.