سُنَنُ النَّسَائِيِّ
Sunan an-Nasa’i 1115
The Book of The At-Tatbiq (Clasping One's Hands Together)
The prohibition of tucking up one's garment when prostrating
أَخْبَرَنَا مُحَمَّدُ بْنُ مَنْصُورٍ الْمَكِّيُّ، عَنْ سُفْيَانَ، عَنْ عَمْرٍو، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ أُمِرَ النَّبِيُّ صلى الله عليه وسلم أَنْ يَسْجُدَ عَلَى سَبْعَةِ أَعْظُمٍ وَنُهِيَ أَنْ يَكُفَّ الشَّعْرَ وَالثِّيَابَ .
It was narrated that Ibn 'Abbas said: "The Prophet (ﷺ) was commanded to prostrate on seven bones and was forbidden to tuck up his hair and garment."
Sunan an-Nasa'i, 1115Sahih (Darussalam)