Musannaf Ibn Abi Shayba 36:337

'Abdah ibn Sulayman narrated to us, from Muhammad ibn 'Amr, who said: Abu Salamah ibn 'Abd al-Rahman, Yahya ibn 'Abd al-Rahman, and 'Abd al-Malik ibn al-Mughirah were discussing the *anfal* (spoils of war), and I was with them. They sent a messenger to Sa'id ibn al-Musayyib to ask him about that. The messenger returned and said: "He refused to tell me anything." He said: Then Sa'id sent his servant, who said: "Sa'id says to you: You sent asking me about the *anfal*, and there is no *nafl* (extra spoils) after the Messenger of Allah, may Allah bless him and grant him peace."