Muwatta Imam Malik (Riwayat Ibn al-Qasim)

And with this same chain of narration, it is narrated from (Sayyiduna Ibn Umar, may Allah be pleased with them both) that the Messenger of Allah, peace and blessings be upon him, sent a detachment (of fighters) towards Najd in which Abdullah bin Umar, may Allah be pleased with them both, was also included. Then they received many camels as spoils of war, so each man received twelve or eleven camels as his share, and then each one was given one additional camel.