(Imām Bukhārī narrates): Abū al-Yamān narrated to us, he said: Shu'aib informed us, from al-Zuhrī, he said: Anas ibn Mālik al-Ansārī, may Allāh be pleased with him, informed us that:

the Messenger of Allāh ﷺ mounted a horse, so his right side was injured. Anas, may Allāh be pleased with him, narrated that one day he led us in one of the prayers while sitting, so we too prayed following him sitting. Then when he gave the salām, he said: The imām is appointed only so that he may be followed; so when he prays standing, you pray standing; and when he performs rukū', you perform rukū'; and when he raises his head from rukū', you also raise your head from rukū'; and when he performs sajdah, all of you perform sajdah; and when he says "Sami'a Allāhu liman hamidah", you say "Rabbanā wa laka al-hamd".