(30) بَابُ مَرْجَعِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مِنَ الأَحْزَابِ وَمَخْرَجِهِ إِلَى بَنِي قُرَيْظَةَ وَمُحَاصَرَتِهِ إِيَّاهُمْ
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 (ﷺ) sent for Sa`d, and the latter came (riding) a donkey and when he approached the Mosque, the Prophet (ﷺ) said to the Ansar, "Get up for your chief or for the best among you." Then the Prophet (ﷺ) 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 (ﷺ) said, "You have judged according to Allah's Judgment," or said, "according to the King's judgment."
Reference: Sahih al-Bukhari 4121
In-book reference: Book 64, Hadith 165
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 5, Book 59, Hadith 447