Prayer (Kitab Al-Salat): Details of Commencing Prayer

Dawud :: Book 3 : Hadith 888

Narrated Abdullah ibn Abbas:

Ibn Abbas reported the Prophet (peace_be_upon_him) as saying: I have been commanded - according to the version of Hammad: Your Prophet (peace_be_upon_him) was commanded - to prostrate on seven (bones), and not to fold back the hair or the clothing.