From Sahih Muslim (Hadith 4560):
It has been narrated by Ibn 'Umar that the Messenger of Allah (ﷺ) 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 (ﷺ) gave an extra camel to each of us
Reference: Muslim 4560