The Arrow at the Trench
During the Battle of the Trench (5 AH / 627 CE), Sa’d ibn Mu’adh was struck by an arrow in the arm — possibly severing or damaging the brachial artery, though he did not die immediately. He reportedly prayed: “O God, if there is still fighting ahead with Quraysh, then keep me alive for it, for there is no people against whom I prefer to fight. But if You have ended the war between us, then make this wound a cause of martyrdom.”
The Arbitration of Banu Qurayza
After the Trench, the Muslim community turned to the tribe of Banu Qurayza, who had violated their treaty with the Prophet during the siege. Both parties accepted Sa’d ibn Mu’adh — as the chief of Aws, the tribe with the closest historical alliance with Banu Qurayza — to arbitrate.
Sa’d was brought on a stretcher, barely able to move. His ruling: the men to be killed, the women and children to be taken as captive or freed, and the property distributed. The Prophet accepted the arbitration, saying it coincided with God’s judgment.
Sa’d died shortly after delivering his ruling. His wound had burst open during the journey.
The Throne
The Prophet’s saying: “The Throne of the Most Merciful shook for Sa’d ibn Mu’adh.” Different explanations exist: some said it referred to the bearers of the divine throne (angels) shaking with joy at his soul’s arrival; others that the divine reality itself acknowledged his passing.
Seventy thousand angels reportedly attended his funeral prayer, according to some narrations.
See also: Seerah Badr, Seerah Uhud, Seerah Khabbab Ibn Al Aratt, Seerah Usama Ibn Zayd, Seerah Abu Ubaydah Ibn Al Jarrah