Ibn 'Abbas reported
The Apostle of Allah (ﷺ) had been commanded that he should prostrate on the seven (bones) and he was forbidden to fold back the hair and clothing. And in the narration transmitted by Abu Rabi' (the words are):" on the seven bones and I was forbidden to fold back the hair and clothing". According to Abu'l-Rabi' (the seven bones are): The hands, the knees, and the (extremities) of the feet and the forehead.
Ibn 'Abbas reported from the Messenger of Allah (ﷺ)
I was commanded to prostrate myself on seven bones and not to fold back clothing or hair.
Ibn 'Abbas reported
The Messenger of Allah (ﷺ) had been commanded to prostrate on seven (bones) and forbidden to fold back hair and clothing.
Ibn Abbas reported that the Messenger of Allah (ﷺ) said
I have been commanded to prostrate myself on seven bones:" forehead," and then pointed with his hand towards his nose, hands, feet, and the extremities of the feet; and we were forbidden to fold back clothing and hair.
Ibn Abbas reported
The Messenger of Allah (ﷺ) said: I was commanded to prostrate myself on the seven (bones) and forbidden to fold back hair and clothing. (The seven bones are): forehead, nose, hands, knees and feet.
It was narrated from Al-'Abbas bin 'Abdul Muttalib that he heard the Messenger of Allah (ﷺ) say
"When a person prostates, he prostates on seven part of the body: His face, his hands, his knees and his feet."
Abdullah b. Abbas reported that he saw 'Abdullah b. al-Harith observing the prayer and (his hair) was plaited behind his head. He ('Abdullah b. 'Abbas) stood up and unfolded them. While going back (from the prayer) he met Ibn 'Abbas and said to him
Why is it that you touched my head? He (Ibn 'Abbas) replied: (The man who observes prayer with plaited hair) is like one who prays with his hands tied behind.