Musannaf Ibn Abi Shayba 36:297

'Abdah ibn Sulayman narrated to us, from Hisham ibn 'Urwah, who said: My father informed me that they submitted to the judgment of the Messenger of Allah (may Allah bless him and grant him peace), and they referred the judgment to Sa'd ibn Mu'adh. Sa'd ibn Mu'adh judged regarding them that their fighters should be killed, their women and offspring should be taken captive, and their wealth should be divided. Hisham said: My father said: I was informed that the Messenger of Allah (may Allah bless him and grant him peace) said: "You have judged regarding them with the judgment of Allah."