When the people of Qurayzah surrendered to the judgment of Saad, the Prophet ﷺ sent for him. He came riding a light-colored donkey, and the Prophet ﷺ said, "Stand up for your master," or "for the best among you."He came and sat down beside the Messenger of Allah ﷺ.
حدثنا حفص بن عمر حدثنا شعبة عن سعد بن إبراهيم عن أبي أمامة بن سهل بن حنيف
أن أهل قريظة لما نزلوا على حكم سعد أرسل إليه النبي ﷺ فجاء على حمار أقمر فقال النبي ﷺ قوموا إلى سيدكم أو إلى خيركم فجاء حتى قعد إلى رسول الله ﷺ
Bukhari narrated it in the Book of Seeking Permission, in the chapter of the Prophet's ﷺ saying, "Stand up for your leader," hadith no. 6262, and Muslim narrated it in the Book of Jihad and Military Expeditions, in the chapter on the permissibility of fighting one who breaks the treaty... etc., hadith no. 1768, from the hadith of Shubah, with this wording.