(44) باب أَعْضَاءِ السُّجُودِ وَالنَّهْىِ عَنْ كَفِّ الشَّعْرِ، وَالثَّوْبِ، وَعَقْصِ الرَّأْسِ، فِي الصَّلاَة
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.
Reference: Sahih Muslim 490 e
In-book reference: Book 4, Hadith 261
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 995