Saʿd had two sons—ʿAmr and ʿAbd Allāh. Their mother was Hind bint Simāk, the paternal aunt of Usayd ibn Ḥuḍayr from the clan of Banū ʿAbd al-Ashhal; she herself was a Companion. Before marrying Saʿd, she had been the wife of his brother Aws ibn Muʿādh. ʿAbd Allāh ibn ʿAmr ibn Saʿd was later killed on the Day of al-Ḥarra.

ʿAmr’s children included Wāqid ibn ʿAmr and several others, said to number nine in total.

Saʿd’s brother ʿAmr fell at the Battle of Uḥud, and their nephew al-Ḥārith ibn Aws was also killed that day while still a youth. All of them had previously fought at Badr. Al-Ḥārith had been struck by the sword on the night Kaʿb ibn al-Ashraf was slain, and his companions had carried him away; afterward he was present at Uḥud, where he died.

Only one Companion is known to have transmitted from Saʿd ibn Muʿādh—ʿAbd Allāh ibn Masʿūd, who narrated the story of Saʿd in Mecca with Umayyah ibn Khalaf; the report is found in Ṣaḥīḥ al-Bukhārī.

The fortress of Banū Qurayẓah lay a few miles outside Medina, and the Prophet ﷺ besieged it for twenty-five nights.

Among the Muslims martyred was Khallād ibn Suwayd al-Anṣārī al-Khazrajī, upon whom a millstone was hurled, crushing him.

During the siege Abū Sinān ibn Muḥṣin—a Badrian Emigrant and the brother of ʿUkāshah ibn Muḥṣin al-Asadī—passed away. He and his son Sinān had both fought at Badr. He was buried in the cemetery of Banū Qurayẓah where the Muslims who lived in their quarter were customarily interred. He lived to the age of forty, though some held that he survived until he pledged allegiance beneath the Tree.