(28) باب مَا بَيْنَ النَّفْخَتَيْنِ
Abu Huraira reported so many ahadith from Allah's Apostle (ﷺ) and amongst these one was this that Allah's Messenger (ﷺ) said:
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.
Reference: Sahih Muslim 2955 c
In-book reference: Book 54, Hadith 179
USC-MSA web (English) reference(deprecated numbering scheme): Book 41, Hadith 7057