Ka'b was born to a father from the ArabTayy tribe and a mother from the Jewish Banu Nadir tribe; he was recognized as belonging to his mother's tribe, in which he was one of the leading men. The order to kill Ka'b is mentioned in numerous hadiths. Muhammad made it clear to his companions that he wished Ka'b killed, saying, "Who is willing to kill Ka’b bin Al-Ashraf who has hurt Allah and His Apostle?" Muhammad bin Maslama volunteered and was aided by several others, including Abu Na'ila. Ibn Maslamah was troubled that this assassination would involve lying to Ka'b, but Muhammad gave him a dispensation to do so. They took Ka'b out for a walk late at night and killed him. Many authors have ascribed evil deeds to Ka'b, with questionable veracity. According to the Encyclopaedia of Islam, following the victory of the Muslims over the Quraysh in the Battle of Badr, in March 624, Ka'b was angry at the execution of a number of Meccan notables who had been captured after that battle. According to Ibn Ishaq, Muhammad called upon his followers to kill Ka'b because the latter "had gone toMecca after Badr and provoked Quraysh against Muhammad." Ka'b went to Mecca, where he composed verses in which he bewailed the victims of Quraysh who had been killed at Badr in a poem. Ibn Hisham's biography of Muhammad reports Ka'b as saying "By Allah, if Muhammad has indeed struck down those people, then it were better to be buried in the earth than to walk upon it!" Shortly thereafter he returned to Medina and composed amatory verses of an insulting nature about the Muslim women." Other sources state that the reason for killing of Ka'b was that he had plotted with a group of Jews to kill Muhammad. The writings of the later commentators such as al-Zamakhshari, al-Tabarsi, al-Razi, al-Baydawi, and al-Asqalani provide another distinct report according to which Ka'b was killed because Gabriel had informed Muhammad about a treaty signed by himself and Aba Sufyan creating an alliance between the Quraysh and forty Jews against Muhammad during Ka'b's visit to Mecca. According to Uri Rubin, some allusions to the existence of an anti-Muslim treaty between Quraysh and Ibn al-Ashraf may be found in the earlier sources. When the Jews learned about the death of Ka'b, "there was not a Jew who did not fear for his life". Earlier, Huyayy bin Akhtab of Banu Nadir tribe had refused to pay blood money for the murder of two Muslims and Abd-Allah bin Ubayy had planned along with allied nomads to attack Muhammad. Muhammad besieged the Banu Nadir and ordered the tribe to leave Medina within ten days. The tribe at first decided to comply, but certain people from Medina who were not believers offered to help Banu al-Nadir fight the Muslims. Huyayy ibn Akhtab, despite opposition from within the tribe, decided to fight, a fight which ended with their surrender although they were allowed to leave and take what possessions they could carry on their camels, with the exception of their weapons which they had to leave behind.
