Musnad Ahmad 31:182

'Abd al-Rahman ibn Mahdi narrated to us, Shu'bah narrated to us, from Sa'd ibn Ibrahim, who said: I heard Abu Umamah ibn Sahl narrating from Abu Sa'id—and he mentioned the meaning of the hadith of Ghundar from Shu'bah regarding the judgment of Sa'd ibn Mu'adh, except that he said: "For I judge that their fighting men be killed and their offspring be taken captive." He [the Prophet] said: "You have judged among them with the judgment of Allah." And he said another time: "You have judged among them with the judgment of the King (al-Malik) or the Sovereign (al-Malik)." 'Abd al-Rahman was in doubt. And 'Affan narrated it to us, saying: "The King (al-Malik)."