Sahih Muslim Book 19, Hadith Number 4332.

Chapter : Spoils of war.

It has been narrated by Ibn ‘Umar that the Messenger of Allah (may peace be upon him) sent an expedition to Najd, and I (also) went with the troops. We got camels and goats as spoils of war, and our share amounted to twelve camels per head, and the Messenger of Allah (may peace be upon him) gave an extra camel to each of us.