Musnad Ahmad 772:5

Abdullah said: Ibrahim ibn al-Hasan al-Bahili, Ubaydullah ibn Umar al-Qawariri, and Muhammad ibn Abi Bakr al-Muqaddami narrated to me, they said: Hammad ibn Zayd narrated to us, from Hajib ibn al-Mufaddal ibn al-Muhallab, from his father, that he heard al-Nu'man ibn Bashir say: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Act justly between your children, act justly between your children, act justly between your children."