The book reports that Ka’b bin al-Ashraf, a wealthy poet, wrote verses against the Prophet ﷺ after Badr, went to Makkah to urge Quraish to war, and on his return composed verses about Muslim women. The Prophet called for volunteers, and a group including Muhammad bin Maslamah and Abu Na’ilah drew him out of his fort at night and killed him.
As the book dates it: night of 14 Rabi’ al-Awwal, 3 A.H.