Hadith
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
Sahih · Abu Ghuddah
Sunan an-Nasa'i 1115 ·Book 12, Hadith 87·Also available on sunnah.com·