The Covenant Breach During the Trench

Banu Qurayza was the last of the three major Jewish tribes of Medina still resident in the city during the Battle of the Trench (5 AH). Unlike Banu Qaynuqa and Banu al-Nadir, who had been expelled after earlier covenant violations, Banu Qurayza had maintained their position and their treaty with the Prophet ﷺ. Their chief, Ka'b ibn Asad, had signed a covenant of mutual defense with the Muslim community and refused early Qurayshi overtures during the trench siege to join the confederates.

Then Huyayy ibn Akhtab — one of the Banu al-Nadir leaders who had been expelled from Medina and who was among the chief organizers of the confederate alliance — came personally to Ka'b ibn Asad. He pressed, argued, and eventually persuaded Ka'b to break the covenant. Banu Qurayza formally aligned with the confederates during the siege, threatening the Muslim community from within while the 10,000-strong confederate army pressed from without. Muslim women and children, sheltered in fortified positions within Medina, were now at risk of attack from the south. The companion Safiyyah bint Abd al-Muttalib — the Prophet's ﷺ aunt — reportedly killed a Banu Qurayza spy who had approached the fortified positions.

The Siege and the Judgment

When the confederate army withdrew and the siege of Medina ended, the Prophet ﷺ declared that the community would not lay down their weapons until they had addressed Banu Qurayza. The hadith preserved in Sahih al-Bukhari records that the Prophet ﷺ announced the march immediately after his return from the trench: "Let no one pray Asr until he has reached Banu Qurayza." The army moved immediately.

The siege of Banu Qurayza's fortified compound lasted approximately twenty-five days. Their expected support — from the confederate allies who had used them and then withdrawn — never came. Eventually, Ka'b ibn Asad asked his people to consider their options: they could accept Islam and thereby be spared; they could kill their own women and children and fight until death; or they could surrender and accept the judgment of Sa'd ibn Mu'adh, the chief of the Aws tribe, who had been their pre-Islamic allies. The tribe chose to surrender unconditionally and accept Sa'd's judgment.

The Judgment of Sa'd ibn Mu'adh

Sa'd ibn Mu'adh was brought on a donkey from where he lay wounded — he had been struck by an arrow in the brachial artery during the trench siege, a wound that would kill him. Before pronouncing judgment, he made the companions swear they would accept his ruling. He then pronounced that the adult males of Banu Qurayza were to be executed, the women and children taken captive, and the property distributed. The Prophet ﷺ said: "You have judged by the judgment of Allah from above seven heavens."

The judgment was carried out. The number executed has been estimated variously in the historical sources — Ibn Hisham gives between 600 and 900. The sentence was applied only to adult males (combatants); one woman, who had killed a Muslim during the siege, was also executed. Women and children were not harmed.

The nature of Sa'd's judgment has been examined extensively by Islamic scholars and by Western historians. Sa'd applied the law found in Deuteronomy (20:10-14) for cities that refused surrender — the same legal standard that Banu Qurayza would themselves have recognized as applicable. The judgment reflected the gravity of the breach: Banu Qurayza had actively collaborated with an enemy army during a siege of Medina, threatening the Muslim community at its most vulnerable moment. Under any recognized law of war of that era, their act constituted capital treason.

The Quranic Reflection

Surah al-Ahzab (33:26-27) addresses the event directly: "And He brought down those who supported them among the People of the Scripture from their strongholds and cast terror into their hearts — a party you killed, and you took captive a party. And He caused you to inherit their land and their homes and their properties and a land which you have not trodden. And ever is Allah over all things competent."

The passage is the Quran's own account of the event, placed within the surah's description of divine assistance during the most dangerous episode of the Medinan period. The terror cast into the hearts of Banu Qurayza — a community that chose surrender over resistance — reflects the same language used about Banu al-Nadir's expulsion in Surah al-Hashr: that divine action, not military force alone, governed the outcome.

The Historical Debate

The siege and judgment of Banu Qurayza have been the subject of debate in modern historical scholarship, with some Western historians questioning the scale of the executions and others raising questions about the application of collective punishment. Islamic scholars have consistently noted several relevant factors: the judgment was made by Sa'd ibn Mu'adh, himself mortally wounded and a member of the Aws tribe that had pre-Islamic alliance with Banu Qurayza — not by the Prophet ﷺ directly; the judgment applied the legal standard that Banu Qurayza themselves would have recognized from their own religious tradition; only combatants (adult males) were executed, not women or children; and the covenant breach occurred during active siege of Medina, when its people faced potential annihilation if the confederates had broken through.

The event sits within the larger pattern of Medina's three covenant breakdowns with its Jewish tribes — each more serious than the last. What Banu Qaynuqa did in the marketplace, and what Banu al-Nadir did in planning an assassination, were serious but contained violations. Banu Qurayza's alignment with a besieging army of 10,000, threatening Medina from within at its most vulnerable moment, was of a categorically different gravity. The graduated severity of consequences — exile, exile with less, judgment by tribal law — reflected the graduated severity of the violations that preceded it. The siege of Banu Qurayza, and its outcome, marked the end of the Medinan period's recurring internal security crises — after 5 AH, no tribe within Medina would again break its covenant with the Prophet ﷺ.

Sources: Sahih al-Bukhari (Kitab al-Maghazi); Sahih Muslim; Ibn Hisham, al-Sira al-Nabawiyya; Ibn Kathir, al-Bidayah wan-Nihayah; Ibn Sa'd, al-Tabaqat al-Kubra; Surah al-Ahzab (33:26-27)