Ayesha reported,

Saad was struck on the day of the Trench. A man from Quraysh called Hibban bin al-Araqah, who was Hibban bin Qays of Banu Muays bin Amir bin Luayy, shot him in the median vein. The Prophet ﷺ pitched a tent for him in the mosque so that he could visit him from close by.When the Messenger of Allah ﷺ returned from the Trench, he laid down his weapons and bathed. Then Jibreel came to him while he was shaking the dust from his head and said, "You have laid down your weapons? By Allah, I have not laid mine down. Go out against them."The Prophet ﷺ asked, "Where?"He pointed toward Banu Qurayzah. So the Messenger of Allah ﷺ went to them, and they surrendered to his judgment. He referred the judgment to Saad, who said, "I rule that their fighting men be killed, that their women and children be taken captive, and that their property be divided."Hisham said, my father told me from Ayesha that Saad had said, "O Allah, You know that there is no people I would rather strive against in Your cause than a people who denied Your Messenger ﷺ and drove him out. O Allah, I think You have ended the war between us and them. If anything remains of the war with Quraysh, then keep me alive for it so that I may strive against them in Your cause. But if You have ended the war, then cause my wound to burst open and let my death be in it."So it burst open at his throat. The first thing that startled the people in a tent of Banu Ghifar in the mosque was the blood flowing toward them. They called out, "People of the tent, what is this coming to us from your direction?" There was Saad, his wound gushing blood, and he died from it.

حدثنا زكرياء بن يحيى حدثنا عبد الله بن نمير حدثنا هشام عن أبيه

عن عائشة رضي الله عنها قالت

أصيب سعد يوم الخندق رماه رجل من قريش يقال له حبان بن العرقة وهو حبان بن قيس من بني معيص بن عامر بن لؤي رماه في الأكحل فضرب النبي ﷺ خيمة في المسجد ليعوده من قريب فلما رجع رسول الله ﷺ من الخندق وضع السلاح واغتسل فأتاه جبريل عليه السلام وهو ينفض رأسه من الغبار فقال قد وضعت السلاح والله ما وضعته اخرج إليهم قال النبي ﷺ فأين فأشار إلى بني قريظة فأتاهم رسول الله ﷺ فنزلوا على حكمه فرد الحكم إلى سعد قال فإني أحكم فيهم أن تقتل المقاتلة وأن تسبى النساء والذرية وأن تقسم أموالهم قال هشام فأخبرني أبي عن عائشة أن سعدا قال اللهم إنك تعلم أنه ليس أحد أحب إلي أن أجاهدهم فيك من قوم كذبوا رسولك ﷺ وأخرجوه اللهم فإني أظن أنك قد وضعت الحرب بيننا وبينهم فإن كان بقي من حرب قريش شيء فأبقني له حتى أجاهدهم فيك وإن كنت وضعت الحرب فافجرها واجعل موتتي فيها فانفجرت من لبته فلم يرعهم وفي المسجد خيمة من بني غفار إلا الدم يسيل إليهم فقالوا يا أهل الخيمة ما هذا الذي يأتينا من قبلكم فإذا سعد يغذو جرحه دما فمات منها رضي الله عنه