Sa'd was wounded on the day of the Battle of the Ditch. A man from the Quraish called Ibn al-Ariqah shot at him an arrow which pierced the artery in the middle of his forearm. The Messenger of Allah ﷺ pitched a tent for him in the mosque and would inquire after him being in close proximity. When he returned from the Ditch and laid down his arms and took a bath, the angel Gabriel appeared to him and he was removing dust from his hair (as if he had just returned from the battle). The latter said: You have laid down arms. By God, we haven't (yet) laid them down. So march against them. The Messenger of Allah ﷺ asked: Where? He pointed to Banu Quraiza. So the Messenger of Allah (may peace he upon him) fought against them. They surrendered at the command of the Messenger of Allah ﷺ, but he referred the decision about them to Sa'd who said: I decide about them that those of them who can fight be killed, their women and children taken prisoners and their properties distributed (among the Muslims).  

أُصِيبَ سَعْدٌ يَوْمَ الْخَنْدَقِ رَمَاهُ رَجُلٌ مِنْ قُرَيْشٍ يُقَالُ لَهُ ابْنُ الْعَرِقَةِ رَمَاهُ فِي الأَكْحَلِ فَضَرَبَ عَلَيْهِ رَسُولُ اللَّهِ ﷺ خَيْمَةً فِي الْمَسْجِدِ يَعُودُهُ مِنْ قَرِيبٍ فَلَمَّا رَجَعَ رَسُولُ اللَّهِ ﷺ مِنَ الْخَنْدَقِ وَضَعَ السِّلاَحَ فَاغْتَسَلَ فَأَتَاهُ جِبْرِيلُ وَهُوَ يَنْفُضُ رَأْسَهُ مِنَ الْغُبَارِ فَقَالَ وَضَعْتَ السِّلاَحَ وَاللَّهِ مَا وَضَعْنَاهُ اخْرُجْ إِلَيْهِمْ فَقَالَ رَسُولُ اللَّهِ ﷺ فَأَيْنَ فَأَشَارَ إِلَى بَنِي قُرَيْظَةَ فَقَاتَلَهُمْ رَسُولُ اللَّهِ ﷺ فَنَزَلُوا عَلَى حُكْمِ رَسُولِ اللَّهِ ﷺ فَرَدَّ رَسُولُ اللَّهِ ﷺ الْحُكْمَ فِيهِمْ إِلَى سَعْدٍ قَالَ فَإِنِّي أَحْكُمُ فِيهِمْ أَنْ تُقْتَلَ الْمُقَاتِلَةُ وَأَنْ تُسْبَى الذُّرِّيَّةُ وَالنِّسَاءُ وَتُقْسَمَ أَمْوَالُهُمْ  

[Machine] There was a man named Lahab ibn al-Arqam who threw a stone at the Prophet Muhammad ﷺ and struck him. The Prophet ﷺ ordered a tent to be set up in the mosque so that he could retaliate when he returned. When the Prophet ﷺ returned from the Khandaq (Trench) and put down his weapons and washed himself, Gabriel ﷺ came to him while shaking the dust off his head and said, "Have you put down your weapons? By Allah, we have not put them down yet. Go to them." The Prophet ﷺ asked, "Where?" Gabriel pointed towards the tribe of Qurayzah. So the Prophet ﷺ went to them, and they accepted his judgement. He handed down the judgement that those who fought should be killed, their women and children taken as captives, and their wealth divided. My father told me that the Prophet ﷺ said, "You have indeed passed judgement on them with the judgement of Allah."  

لَهُ حَبَّانُ بْنُ الْعَرِقَةِ رَمَاهُ فِي الْأَكْحَلِ فَضَرَبَ عَلَيْهِ رَسُولُ اللهِ ﷺ خَيْمَةً فِي الْمَسْجِدِ لِيَعُودَهُ مِنْ قَرِيبٍ فَلَمَّا رَجَعَ رَسُولُ اللهِ ﷺ مِنَ الْخَنْدَقِ وَوَضَعَ السِّلَاحَ وَاغْتَسَلَ أَتَاهُ جِبْرِيلُ عَلَيْهِ السَّلَامُ وَهُوَ يَنْفُضُ رَأْسَهُ مِنَ الْغُبَارِ فَقَالَ قَدْ وَضَعْتَ السِّلَاحَ؟ وَاللهِ مَا وَضَعْنَاهَا اخْرُجْ إِلَيْهِمْ قَالَ رَسُولُ اللهِ ﷺ فَأَيْنَ؟ قَالَ هَهُنَا وَأَشَارَ إِلَى بَنِي قُرَيْظَةَ فَخَرَجَ رَسُولُ اللهِ ﷺ إِلَيْهِمْ فَنَزَلُوا عَلَى حُكْمِ رَسُولِ اللهِ ﷺ فَرَدَّ الْحُكْمَ فِيهِمْ إِلَى سَعْدٍ قَالَ فَإِنِّي أَحْكُمُ فِيهِمْ أَنْ تُقْتَلَ الْمُقَاتِلَةُ وَتُسْبَى الذُّرِّيَّةُ وَتُقْسَمَ أَمْوَالُهُمْ قَالَ أَبِي فَأُخْبِرْتُ أَنَّ رَسُولَ اللهِ ﷺ قَالَ لَقَدْ حَكَمْتَ فِيهِمْ بِحُكْمِ اللهِ