Ka'b ibn al-Ashraf

Kaʿb ibn al-Ashraf was the son of an Arab father from the tribe of Banū Nabhan (who had fled his own people after committing murder and was subsequently adopted by the Banū Naḍīr of Yathrib) and a Jewish mother from Banū Naḍīr. He was thus both fully Arab by lineage and fully Jewish by religion and upbringing. He rose to become one of the ashrāf (nobles) of Banū Naḍīr, wealthy, handsome, and renowned as a gifted poet. He owned his own fortress on the outskirts of Madinah.

His animosity to Islam manifested early in the Madinan period. When the qibla was changed from Jerusalem to Makkah, Kaʿb publicly mocked the Muslims, Allah quoted him in Q 2:142: 'The foolish among people will say: what turned them from their qibla?' When the command for zakāt was revealed, Kaʿb went to his Anṣārī acquaintances and discouraged them from paying, warning that they would lose their wealth, referenced in Q 4:37.

When news of the Battle of Badr reached Madinah, Kaʿb responded with mocking sarcasm: 'If Muḥammad has truly killed all these nobles, then it is better to be inside the earth than outside it.' Then, despite the treaty of Madinah binding him to the Muslim community, he undertook a secret journey to Makkah and personally met with Abū Sufyān to form a political-military alliance against the Muslims. During that meeting, Abū Sufyān asked him which religion was more beloved to Allah, Islam or paganism, and Kaʿb declared that the Qurayshi pagans were 'more rightly guided' (ahda) than the Muslims. Allah quoted this private conversation in Q 4:51.

He also composed explicit erotic poetry naming specific Muslim women, in what was understood as a deliberate attempt to incite Qurayshi men against them, crossing every line of the social code even of that era.

These combined acts, treaty violation, secret military alliance with the enemy, and provocative attack on the Muslim community's honor, led the Prophet ﷺ to authorize his elimination. Muḥammad ibn Maslamah, Abū Nāʾilah (Kaʿb's own foster brother), and al-Ḥārith ibn Aws volunteered. On the night of the 14th of Rabīʿ al-Awwal, a full moon, they went to his fortress. Kaʿb's new wife begged him not to go out, saying 'you are a man at war.' He went anyway, trusting Abū Nāʾilah as his foster brother. Abū Nāʾilah used the ruse of smelling his hair, grabbed him, and the others completed the deed. Al-Ḥārith ibn Aws was seriously wounded in the melee (by the others' blades) and was healed by the Prophet ﷺ placing saliva on his wounds.

Scholars differ on whether this occurred before Uḥud (Ibn Isḥāq, Ibn Hishām, al-Wāqidī) or shortly before the Battle of Banū Naḍīr after Uḥud (al-Baghawī, Muqātil ibn Sulaymān, al-Ṣāliḥī in Subul al-Hudā war-Rashād). The second group additionally holds that Kaʿb was the one who conceived the plot to poison the Prophet ﷺ at a meal, a plan executed by Banū Naḍīr after his death.