Narrated Nafi from Ibn Umar: Allah's Apostle sent a Sariya towards Najd, and Abdullah bin 'Umar was in the Sariya. They gained a great number of camels as war booty. The share of each one of them was twelve or eleven camels, and they were given an extra camel each.
— Sahih Bukhari, Volume 4, Book 53: One-fifth of Booty to the Cause of Allah (Khumus), Hadith #362