Sahih Muslim 4596

It has been narrated on the authority of Abu Sa'id al-Khudri who said:The people of Quraiza surrendered accepting the decision of Sa'd b. Mu'adh about them. Accordingly, the Messenger of Allah (ﷺ) sent for Sa'd who came to him riding a donkey. When he approached the mosque, the Messenger of Allah (ﷺ) said to the Ansar: Stand up to receive your chieftain. Then he said (to Sa'd): These people have surrendered accepting your decision. He (Sa'd) said: You will kill their fighters and capture their women and children. (Hearing this), the Prophet (ﷺ) said: You have adjudged by the command of God. The narrator is reported to have said: Perhaps he said: You have adjudged by the decision of a king. Ibn Muthanna (in his version of the tradition) has not mentioned the alternative words