In the oasis of Yithrab (Medina) in 622 CE, Muhammad arrived with his Arab Muslim followers. He was there to mediate a dispute between the pagan Arab Aws and their Jewish allies, the Qurayza and Nadir tribes, against the pagan Arab Khazraj and their Jewish allies, the Qaynuqa. Muhammad drafted the Constitution of Medina, granting religious freedom, economic independence, and treaties of peace and mutual defense between the tribes. Ka’b Ibn Asad was the chief of the Qurayza tribe and agreed to the treaty on behalf of his people.
The nature of this treaty is uncertain. Muhammad was not himself literate so it may well have been an oral agreement, or a series of oral agreements made over time. The exact nature of what everyone consented to isn’t as well preserved as we might like. (History sads.) It also means there are disputes about exactly who did or did not violate the treaty made in the 7th century. Muslim scholars tend to think it was the Jewish tribes; Jewish scholars tend to think it was the Muslims. I’m going to present some of both possibilities in the following.
In April 624 when Muhammad came back victorious from a battle with his estranged tribe in Mecca, he expelled the Qaynuqa Jewish tribe of goldsmiths. A Muslim woman was allegedly accosted at a jeweler’s shop by Jewish men. They allegedly told her to unpin her face veil, and tried to pull it off themselves. Then one caught at her dress so that when she tried to leave it ripped and exposed her. A Muslim man was allegedly enraged into murdering the Jewish man who undressed her. Soon the city was overtaken with reprisals and revenge killings.
It’s also a possibility Muhammad wanted to eliminate a political threat that persisted in trading with his hated relatives in Mecca. The Qayunqa goldsmiths were loyal to the Khazraj, not to Islam. The hate crime hysteria was a perfect moment to seize on for a siege. Muhammad held the Qaynuqa fortress siege for two weeks before defeating and exiling them from their home for five centuries. Most moved on to join existing Jewish communities in Syria. Some Jews stayed behind, converting to Islam. Muhammad kept 1/5 of the spoils for himself and divided the rest among his people.
That September (624) Muhammad instructed Muslims to “kill every Jew whom you can overpower”, which the Jews of Medina took as both a threat and a violation of the treaty. Ka’b Ibn Asad, chief of the Qurayza tribe, and Huyayy Ibn Akhtab, chief of the Nasir tribe, confronted him about this. Muhammad warned them that if they were so bold in the future or spoke against him, ” swords will be unsheathed again.” A new contract was agreed upon and deposited with Muhammad’s son-in-law Ali. Exact details are unknown but it probably withdrew the commandment to kill every Jew.
“The Jews of Arab Lands” (1979) by Norman Stillman
Encyclopedia of Islam, Edited by P. Bearman, et.al