When the fight at the trench and the affair of the B. Qurayza were over, the matter of Sallam b. Abu'l-Huqayq known as Abu Rafi` came up in connection with those who had collected the mixed tribes together against the apostle. Now Aus had killed Ka`b b. al-Ashraf before Uhud because of his enmity towards the apostle and because he instigated men against him, so Khazraj asked and obtained the apostle's permission to kill Sallam who was in Khaybar.

Muhammad b. Muslim b. Shihab al-Zuhri from `Abdullah b. Ka`b b. Malik told me: One of the things which God did for His apostle was that these two tribes of the Ansar, Aus and Khazraj, competed the one with the other like two stallions: if Aus did anything to the apostle's advantage Khazraj would say, "They shall not have this superiority over us in the apostle's eyes and in Islam" and they would not rest until they could do something similar. If Khazraj did anything Aus would say the same.

When Aus had killed Ka'b for his enmity towards the apostle, Khazraj used these words and asked themselves what man was as hostile to the apostle as Ka'b? And then they remembered Sallam, who was in Khaybar and asked and obtained the apostle's permission to kill him.

Five men of B.Salima of Khazraj went to him: 'Abdullah b.`Atik; Mas`ud b. Sinan; `Abdullah b. Unays; Abu Qatada al-Harith b. Rib'i; and Khuza`i b. Aswad, an ally from Aslam. As they left, the apostle appointed `Abdullah b.`Atik as their leader, and he forbade them to kill women or children. When they got to Khaybar they went to Sallam's house by night, having locked every door in the settlement on the inhabitants. Now he was in an upper chamber of his to which a ladder led up. They mounted this until they came to the door and asked to be allowed to come in. His wife came out and asked who they were and they told her that they were Arabs in search of supplies. She told them that their man was here and that they could come in. When we entered we bolted the door of the room on her and ourselves fearing lest something should come between us and him. His wife shrieked and warned him of us, so we ran at him with our swords as he was on his bed. The only thing that guided us in the darkness of the night was his whiteness like an Egyptian blanket. When his wife shrieked one of our number would lift his sword against her; then he would remember the apostle's ban on killing women and withdraw his hand; but for that we would have made an end of her that night. When we had smitten him with our swords `Abdullah b. Unays bore down with his sword into his belly until it went right through him, as he was saying Qatni, qatni, i.e. it's enough.

We went out. Now `Abdullah b.`Atik had poor sight, and fell from the ladder and sprained his arm (729) severely, so we carried him until we brought him to one of their water channels and went into it. The people lit lamps and went in search of us in all directions until, despairing of finding us, they returned to their master and gathered round him as he was dying. We asked each other how we could know that the enemy of God was dead, and one of us volunteered to go and see; so off he went and mingled with the people. He said, "I found his wife and some Jews gathered round him. She had a lamp in her hand and was peering into his face and saying to them 'By God, I certainly heard the voice of `Abdullah b.`Atik. Then I decided I must be wrong and thought, "How can Ibn`Atik be in this country?"' Then she turned towards him, looking into his face, and said, 'By the God of the Jews he is dead!' Never have I heard sweeter words than those."

Then he came to us and told us the news, and we picked up our companion and took him to the apostle and told him that we had killed God's enemy. We disputed before him as to who had killed him, each of us laying claim to the deed. The apostle demanded to see our swords and when he looked at them he said, "It is the sword of `Abdullah b. Unays that killed him; I can see traces of food on it"

Siratu'l Rasul, vs. 714-715

The text continues:

Hassan b. Thabit mentioning the killing of Ka`b and Sallam said:

God, what a fine band you met,
O Ibnu'l-Huqayq and Ibnu'l-Ashraf!
They went to you with sharp swords,
Brisk as lions in a tangled thicket,
Until they came on you in your dwelling
And made you drink death with their swift-slaying swords,
Despising every risk of hurt.

Far from being embarrassed these assassinations are celebrated as victories for Islam. They are an integral part of the spread of Islam.

The titles of the stories themselves are interesting in their sequence:

The Raid on B. Qurayza
The Killing of Sallam Ibn Abu'l-Huqayq
`Amr b. Al-`As and Khalid b. Al-Walid accept Islam
The Attack on b. Lihyan
The Attack on Dhu Qarad
The Raid on b. Al-Mustaliq
The stories naturally alter in their attacks on tribes or cities or settlements and the embracing of Islam by important people and the next attacks, interspersed with assassinations of Muhammad's personal enemies... All of this is naturally part of the progress of Islam. Without any problem in the opinion of Ibn Hisham.