(Imām Bukhārī narrates): Abū al-Nu'mān narrated to us, he said: Hammād narrated to us, and he is Ibn Zaid, from 'Amr ibn Dīnār, from Tāwūs, from Ibn 'Abbās, may Allāh be pleased with them both, he narrates that:
the Prophet ﷺ was commanded that he should perform sajdah upon seven bones, and neither fold up the garments nor the hair.
حَدَّثَنَا أَبُو النُّعْمَانِ، قَالَ حَدَّثَنَا حَمَّادٌ ـ وَهْوَ ابْنُ زَيْدٍ ـ عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ طَاوُسٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ أُمِرَ النَّبِيُّ صلى الله عليه وسلم أَنْ يَسْجُدَ عَلَى سَبْعَةِ أَعْظُمٍ، وَلاَ يَكُفَّ ثَوْبَهُ وَلاَ شَعَرَهُ.
Reference: Sahih Al Bukhari 815