سُنَنُ النَّسَائِيِّ
Sunan an-Nasa’i 1093
The Book of The At-Tatbiq (Clasping One's Hands Together)
On how many (parts of the body) does one prostrate on?
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ عَمْرٍو، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ أُمِرَ النَّبِيُّ صلى الله عليه وسلم أَنْ يَسْجُدَ عَلَى سَبْعَةِ أَعْضَاءٍ وَلاَ يَكُفَّ شَعْرَهُ وَلاَ ثِيَابَهُ .
It was narrated that Ibn 'Abbas said: "The Prophet (ﷺ) was commanded to prostrate on seven parts of his body and not to tuck up his hair or his garment."
Sunan an-Nasa'i, 1093Sahih (Darussalam)