Musnad Ahmad 33:656

Hujayn and Yunus narrated to us, they said: Al-Layth ibn Sa’d narrated to us, from Abu al-Zubayr, from Jabir, that he said: Sa’d ibn Mu’adh was struck by an arrow on the day of the Confederates (al-Ahzab), and they severed his brachial artery. The Messenger of Allah, peace and blessings of Allah be upon him, cauterized it with fire, but his hand swelled. He cauterized it again, and his hand swelled. He cauterized it a third time, and his hand swelled, so he left it alone. When he saw that, he said: "O Allah, do not take my soul until You cool my eyes regarding Banu Qurayza." His vein then stopped bleeding, and not a single drop fell until they surrendered to the judgment of Sa’d. He (the Prophet) sent for him, and he judged that their men should be killed, and their women and children should be spared, so that the Muslims might be aided by them. The Messenger of Allah, peace and blessings of Allah be upon him, said: "You have hit the judgment of Allah regarding them." They were four hundred. When he finished killing them, his vein burst open, and he died.