“When a person prostrates, seven parts of his body prostrate with him: His face, his two hands, his two knees, and his two feet.”
أَنَّهُ سَمِعَ النَّبِيَّ ﷺ يَقُولُ إِذَا سَجَدَ الْعَبْدُ سَجَدَ مَعَهُ سَبْعَةُ آرَابٍ وَجْهُهُ وَكَفَّاهُ وَرُكْبَتَاهُ وَقَدَمَاهُ