Volume 4, Book 52, Number 270 :
Narrated by Jabir bin ‘Abdullah (radiallaahu `anhu)
The Prophet (sallallaahu `alayhi wasallam) said, “Who is ready to kill Ka’b bin Al-Ashraf who has really hurt Allah and His Apostle?” Muhammad bin Maslama (radiallaahu `anhu) said, “O Allah’s Apostle! Do you like me to kill him?” He replied in the affirmative. So, Muhammad bin Maslama (radiallaahu `anhu) went to him (i.e. Ka’b) and said, “This person (i.e. the Prophet) has put us to task and asked us for charity.” Ka’b replied, “By Allah, you will get tired of him.” Muhammad (radiallaahu `anhu) said to him, “We have followed him, so we dislike to leave him till we see the end of his affair.” Muhammad bin Maslama (radiallaahu `anhu) went on talking to him in this way till he got the chance to kill him.
Volume 4, Book 52, Number 271 :
Narrated by Jabir (radiallaahu `anhu)
The Prophet (sallallaahu `alayhi wasallam) said, “Who is ready to kill Ka’b bin Ashraf (i.e. a Jew).” Muhammad bin Maslama (radiallaahu `anhu) replied, “Do you like me to kill him?” The Prophet (sallallaahu `alayhi wasallam) replied in the affirmative. Muhammad bin Maslama (radiallaahu `anhu) said, “Then allow me to say what I like.” The Prophet (sallallaahu `alayhi wasallam) replied, “I do (i.e. allow you).”
Safi-ur-Rahmna Mubarakpuri writes in The Sealed Nectar:
Ka‘b bin Al-Ashraf was the most resentful Jew at Islam and the Muslims, the keenest on inflicting harm on the Messenger of Allâh and the most zealous advocate of waging war against him. He belonged to Tai’ tribe but his mother to Banu Nadeer. He was a wealthy man known for his handsomeness, and a poet living in luxury in his fort south east of Madinah at the rear of Banu Nadeer’s habitations.
On hearing the news of Badr, he got terribly exasperated and swore that he would prefer death to life if the news was true. When this was confirmed he wrote poems satirizing Muhammad , eulogizing Quraish and enticing them against the Prophet . He then rode to Makkah where he started to trigger the fire of war, and kindle rancour against the Muslims in Madinah. When Abu Sufyan asked him which religion he was more inclined to, the religion of the Makkans or that of Muhammad and his companions, he replied that the pagans were better guided. With respect to this situation, Allâh revealed His Words:
“Have you not seen those who were given a portion of the Scripture? They believe in Jibt and Taghût, and say to the disbelievers that they are better guided as regards the way than the believers (Muslims).” [4:51]
He then returned to Madinah to start a fresh campaign of slanderous propaganda that took the form of obscene songs and amatory sonnets with a view to defaming the Muslim women.
At this stage, the situation became unbearable and could no longer be put up with. The Prophet gathered his men and said: “Who will kill Ka‘b bin Al-Ashraf? He had maligned Allâh, and His Messenger.” Thereupon, Muhammad bin Maslamah, ‘Abbad bin Bishr, Al-Harith bin Aws, Abu ‘Abs bin Hibr and Salkan bin Salamah, Ka‘b’s foster brother, volunteered to do the job.
Muhammad bin Maslamah said: “O Messenger of Allâh, do you wish that I should kill him?” He said: “Yes.” He said: “Permit me to talk (to him in the way I deem fit).” He said: “Talk (as you like).” So, Muhammad bin Maslamah came to Ka‘b and talked to him, saying: “This man (i.e. the Prophet ) has made up his mind to collect charity (from us) and this has put us to a great hardship.” When he heard this, Ka‘b said: “By Allâh you will be put to more trouble by him.” Muhammad bin Maslamah answered: “No doubt, now we have become his followers and we do not like to forsake him until we see what turn his affairs will take. I want that you should give me a loan.” He said: “What will you mortgage?” Muhammad answered: “What do you want?” The immoral and heartless Jew demanded women and children as articles of security against the debt. Muhammad said: “Should we pledge our women whereas you are the most handsome of the Arabs; and the son of one of us may be abused by saying that he was pledged for two wasq (measurement unit of weight) of dates but we can pledge you (our) weapons.” Ka‘b agreed. Salkan bin Salamah, Abu Na’ilah, at another time, went to see Ka‘b for the same purpose and there were more or less the same subjects, only that Abu Na’ilah would bring him some companions. The plan was successful and provided for the presence of both men and weapons. On Rabi‘ Al-Awwal 14th, at night, the year 3 A.H. the people said good bye to the Prophet and set out in the Name of Allâh to implement the carefully drawn plan. The Prophet stayed back praying for them and supplicating Allâh to render them success. The men went and called upon him at night. He came down although his wife warned him not to meet them alleging that: “I hear a voice which sounds like the voice of murder.” He said: “It is only Muhammad bin Maslamah and my foster brother Abu Na’ilah. When a gentleman is called at night even if he be pierced with a spear, he should respond to the call.” Abu Na’ilah said to his companions: “As he comes down, I will extend my hand towards his head to smell and when I hold him fast, you should do your job.” So when he came down, they talked together for about an hour. They then invited him to go out and spend a nice time in the moonlight. On the way out, Abu Na’ilah remarked: “I smell the nicest perfume from you.” Ka‘b said: “Yes, I have with me a mistress who is the most scented of the women of Arabia.” Abu Na’ilah again said: “Allow me to smell (the scent on your head)”. He said: “Yes, you may smell.” So he caught it and smelt. Then he said: “Allow me to do so(once again).” He then held his head fast and said to his companions: “Do your job.” And they killed him. The group of men came back after fulfilling their mission. One of them Al-Harith bin Aws was wounded by mistake with the swords of his men, and was bleeding badly. When they reached Baqee‘ Al-Gharqad, they shouted, “Allâh is Great”. The Prophet heard them and realized that they had killed the enemy of Allâh. As they saw him, he said: “Cheerful faces are yours.” In reply, they said: “And yours O Messenger of Allâh.” They handed the head of the tyrant over to him. He entertained Allâh’s praise for their success. He then applied his saliva to Al-Harith’s wound and it healed on the spot.
When the Jews learned about the death of their tyrant, Ka‘b bin Al-Ashraf, they were scared and even their stonelike hearts were in the grip of inexpressible panic. They realized that the Messenger of Allâh would thenceforth never hesitate to use force when good words and admonition failed. They remained silent and resigned, and faked adherence to covenants.
Now the Prophet was free to collect his thoughts and give himself up to resolving foreign affairs, and facing dangers that could be carried with hostile wind blowing again from Makkah.
Watch this video for a detailed analysis of this incident by Yasir Qadhi: