Sahih Muslim Book 41, Hadith Number 7057.

Chapter : The Interval between two Blowings of the Trumpet.

Abu Huraira reported so many ahadith from Allah’s Apostle (may peace be upon him) and amongst these one was this that Allah’s Messenger (may peace be upon him) 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.