It was narrated from ‘Abbas bin ‘Abdul-Muttalib that he heard the Prophet (ﷺ) say:“When a person prostrates, seven parts of his body prostrate with him: His face, his two hands, his two knees, and his two feet.”
حَدَّثَنَا يَعْقُوبُ بْنُ حُمَيْدِ بْنِ كَاسِبٍ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ أَبِي حَازِمٍ، عَنْ يَزِيدَ بْنِ الْهَادِ، عَنْ مُحَمَّدِ بْنِ إِبْرَاهِيمَ التَّيْمِيِّ، عَنْ عَامِرِ بْنِ سَعْدٍ، عَنِ الْعَبَّاسِ بْنِ عَبْدِ الْمُطَّلِبِ، أَنَّهُ سَمِعَ النَّبِيَّ ـ صلى الله عليه وسلم ـ يَقُولُ " إِذَا سَجَدَ الْعَبْدُ سَجَدَ مَعَهُ سَبْعَةُ آرَابٍ: وَجْهُهُ وَكَفَّاهُ وَرُكْبَتَاهُ وَقَدَمَاهُ " .
IbnMaja
Establishing the Prayer and the Sunnah Regarding Them • Hadith 885