Sahih Muslim 490 d
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.
حَدَّثَنَا مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا بَهْزٌ، حَدَّثَنَا وُهَيْبٌ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ طَاوُسٍ، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ أُمِرْتُ أَنْ أَسْجُدَ عَلَى سَبْعَةِ أَعْظُمٍ الْجَبْهَةِ - وَأَشَارَ بِيَدِهِ عَلَى أَنْفِهِ - وَالْيَدَيْنِ وَالرِّجْلَيْنِ وَأَطْرَافِ الْقَدَمَيْنِ وَلاَ نَكْفِتَ الثِّيَابَ وَلاَ الشَّعْرَ ‏"‏ ‏.‏