Sahih Bukhari Volume 4, Book 52, Hadith Number 280.

Narated By Abu Sa’id Al-Khudri : When the tribe of Bani Quraiza was ready to accept Sad’s judgment, Allah’s Apostle sent for Sad who was near to him. Sad came, riding a donkey and when he came near, Allah’s Apostle said (to the Ansar), “Stand up for your leader.” Then Sad came and sat beside Allah’s Apostle who said to him. “These people are ready to accept your judgment.” Sad said, “I give the judgment that their warriors should be killed and their children and women should be taken as prisoners.” The Prophet then remarked, “O Sad! You have judged amongst them with (or similar to) the judgment of the King Allah.”