Musnad Ahmad 33:853

'Abd al-Razzaq narrated to us, Sufyan informed us, from Abu al-Zubayr, from Jabir, who said: Abu Madhkur emancipated a slave of his called Ya'qub al-Qibti, to take effect after his death. This reached the Prophet, peace and blessings of Allah be upon him, and he said: "Does he have any wealth other than him?" They said: "No." He said: "Who will buy him from me?" So Nu'aym ibn al-Nahham, the son-in-law of 'Umar ibn al-Khattab, bought him for eight hundred. The Prophet, peace and blessings of Allah be upon him, then said: "Spend it on yourself. If there is any surplus, then on your family. If there is any surplus, then on your relatives. If there is any surplus, then here, and here, and here."