" إِذَا سَجَدَ الْعَبْدُ سَجَدَ مَعَهُ سَبْعَةُ آرَابٍ وَجْهُهُ وَكَفَّاهُ وَرُكْبَتَاهُ وَقَدَمَاهُ "
It was narrated from 'Abbas bin 'Abdul-Muttalib that: He heard the Messenger of Allah (ﷺ) say: "When a person prostrates, seven parts of his body prostrate with him: his forehead, his two hands, his two knees and his two feet."