Sunan Ibn Majah Book 5, Hadith 84
“We
used to feel sorry for the Messenger of Allah (ﷺ) because he
took
pains to keep his arms away from his sides when he prostrated.”
“When a person prostrates, seven parts of his body prostrate with him: His face, his two hands, his two knees, and his two feet.”
“When the following was revealed: ‘So glorify the Name of your Lord, the Most Great’, the Messenger of Allah (ﷺ) said to us: ‘Say this in your Ruku’.’ And when the following was revealed: ‘Glorify the Name of your Lord, the Most High.’ the Messenger of Allah (ﷺ) said to us: ‘Say this in your prostrations.’”