So you have problem with the ruling? Or me?
It is related that Jabir was heard to say that the Messenger of Allah, may Allah bless him and grant him peace, said, **“Who will deal with Ka’b ibn al-Ashraf? He has insulted Allah and His Messenger.” **Muhammad ibn Maslama said, ** “Do you want me to kill him, Messenger of Allah?” He replied, “Yes.” He went to him and said, “This one - meaning the Prophet, may Allah bless him and grant him peace, - has imposed on us and asked us for sadaqa.” He said, “As well. By Allah, you will be tired of him.” He said, “We have followed him and we dislike to leave him until we see where his affair will end.” He continued speaking to him until he was able to kill him. **
It is related from Jabir that the Prophet, may Allah bless him and grant him peace, said, **“Who will deal with Ka’b ibn al-Ashraf?” Muhammad ibn Maslama asked, “Do you want me to kill him?” He answered, “Yes.” He said, “Then give me permission to speak.” He said, “I have done it.”
[Bukhari]
**