Sahih Muslim #4596 · The Book of Jihad and Expeditions

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.