Sahih al-Bukhari, Volume 5, Book 59, Hadith 447 (USC-MSA) ⓘ

Narrated Abu Sa`id Al-Khudri: The people of (Banu) Quraiza agreed to accept the verdict of Sa`d bin Mu`adh. So the Prophet sent for Sa`d, and the latter came (riding) a donkey and when he approached the Mosque, the Prophet said to the Ansar, "Get up for your chief or for the best among you." Then the Prophet said (to Sa`d)." These (i.e. Banu Quraiza) have agreed to accept your verdict." Sa`d said, "Kill their (men) warriors and take their offspring as captives, "On that the Prophet said, "You have judged according to Allah's Judgment," or said, "according to the King's judgment."

حَدَّثَنِي مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا غُنْدَرٌ، حَدَّثَنَا شُعْبَةُ، عَنْ سَعْدٍ، قَالَ سَمِعْتُ أَبَا أُمَامَةَ، قَالَ سَمِعْتُ أَبَا سَعِيدٍ الْخُدْرِيَّ ـ رضى الله عنه ـ يَقُولُ نَزَلَ أَهْلُ قُرَيْظَةَ عَلَى حُكْمِ سَعْدِ بْنِ مُعَاذٍ، فَأَرْسَلَ النَّبِيُّ صلى الله عليه وسلم إِلَى سَعْدٍ، فَأَتَى عَلَى حِمَارٍ، فَلَمَّا دَنَا مِنَ الْمَسْجِدِ قَالَ لِلأَنْصَارِ ‏"‏ قُومُوا إِلَى سَيِّدِكُمْ ـ أَوْ ـ خَيْرِكُمْ ‏"‏‏.‏ فَقَالَ ‏"‏ هَؤُلاَءِ نَزَلُوا عَلَى حُكْمِكَ ‏"‏‏.‏ فَقَالَ تَقْتُلُ مُقَاتِلَتَهُمْ وَتَسْبِي ذَرَارِيَّهُمْ‏.‏ قَالَ ‏"‏ قَضَيْتَ بِحُكْمِ اللَّهِ ‏"‏‏.‏ وَرُبَّمَا قَالَ ‏"‏ بِحُكْمِ الْمَلِكِ ‏"‏‏.‏