سنن أبي داود

‘A’ishah said; The Messenger of Allah (ﷺ) prayed in his house sitting and the people prayed behind him standing. He made a sign to them (asking them) to sit down. When he finished the prayer, he said : 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.