Sunan Ibn Majah 863

‘Abbas bin Sahl As-Sa’di said:“Abu Humaid, Abu Usaid As-Sa’di, Sahl bin Sa’d, and Muhammad bin Maslamah came together and spoke about the prayer of the Messenger of Allah (ﷺ). Abu Humaid said: ‘I am the most knowledgeable of you about the prayer of the Messenger of Allah (ﷺ). The Messenger of Allah (ﷺ) stood up and said Allahu Akbar, and raised his hands, then he raised them when he said Allahu Akbar for Ruku’, then he stood up and raised his hands, and stood straight until every bone had returned to its place.’”