Sahih Muslim 2955
Sahih Muslim · Book 54: The Book of Tribulations and Portents of the Last Hour · Between The Blasts (Of The Trumpet)
Abu Huraira reported so many ahadith from Allah's Apostle (ﷺ) and amongst these one was this that Allah's Messenger (ﷺ) said:
حَدَّثَنَا مُحَمَّدُ بْنُ رَافِعٍ ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ ، حَدَّثَنَا مَعْمَرٌ ، عَنْ هَمَّامِ بْنِ مُنَبِّهٍ ، قَالَ هَذَا مَا حَدَّثَنَا أَبُو هُرَيْرَةَ ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم فَذَكَرَ أَحَادِيثَ مِنْهَا وَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ فِي الإِنْسَانِ عَظْمًا لاَ تَأْكُلُهُ الأَرْضُ أَبَدًا فِيهِ يُرَكَّبُ يَوْمَ الْقِيَامَةِ " . قَالُوا أَىُّ عَظْمٍ هُوَ يَا رَسُولَ اللَّهِ قَالَ " عَجْبُ الذَّنَبِ " .
There is a bone in the human being which the earth would never consume and it is from this that new bodies would be reconstituted (on the Day of Resurrection). They said: Allah's Messenger, which bone is that? Thereupon he said: It is the spinal bone.