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: Messenger of Allah, which bone is that? Thereupon he said: It is the spinal bone.
عَنْ رَسُولِ اللَّهِ ﷺ فَذَكَرَ أَحَادِيثَ مِنْهَا وَقَالَ رَسُولُ اللَّهِ ﷺ إِنَّ فِي الإِنْسَانِ عَظْمًا لاَ تَأْكُلُهُ الأَرْضُ أَبَدًا فِيهِ يُرَكَّبُ يَوْمَ الْقِيَامَةِ قَالُوا أَىُّ عَظْمٍ هُوَ يَا رَسُولَ اللَّهِ قَالَ عَجْبُ الذَّنَبِ