Messenger of Allah Saying: "When the worshipper prostrates with him: His face, his hands, his knees, and his feet."  

أَنَّهُ سَمِعَ رَسُولَ اللَّهِ ﷺ يَقُولُ إِذَا سَجَدَ الْعَبْدُ سَجَدَ مَعَهُ سَبْعَةُ آرَابٍ وَجْهُهُ وَكَفَّاهُ وَرُكْبَتَاهُ وَقَدَمَاهُ قَالَ وَفِي الْبَابِ عَنِ ابْنِ عَبَّاسٍ وَأَبِي هُرَيْرَةَ وَجَابِرٍ وَأَبِي سَعِيدٍ  

"The Prophet ordered that one prostrate on seven bones and that he not gather his hair nor his garment."  

أُمِرَ النَّبِيُّ ﷺ أَنْ يَسْجُدَ عَلَى سَبْعَةِ أَعْظُمٍ وَلاَ يَكُفَّ شَعْرَهُ وَلاَ ثِيَابَهُ