Abu Dawud Book 8, Hadith Number 2749.

Narated By Amr ibn Abasah : The Apostle of Allah (PBUH) led us in prayer facing a camel which had been taken in booty, and when he had given the salutation, he took a hair from the camel’s side and said: I have no right as much as this of your booty, but only to the fifth. and the fifth is returned to you.