Volume 6, Book 60, Number 338:
Narrated Abu Huraira:
The Prophet said, “Between the two blowing of the trumpet there will be forty.” The people said, “O
Abu Huraira! Forty days?” I refused to reply. They said, “Forty years?” I refused to reply and added:
Everything of the human body will decay except the coccyx bone (of the tail) and from that bone Al –
lah will reconstruct the whole body.