Sahih al-Bukhari 4121
صحيح البخاري#4121SahihNarrated 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 64:165