Musnad Ahmad 33:446

Abu 'Amir al-'Aqadi narrated to us, Qurrah narrated to us, from 'Amr ibn Dinar, from Jabir, who said: While the Messenger of Allah (peace and blessings of Allah be upon him) was distributing the spoils of Hunayn, a man stood up to him and said: "Be just." He (the Prophet) said: "You have become wretched if I am not just."