Bukhari

Hadith Commentary:
In all the aforementioned hadiths, there is mention in one way or another of the battle with the Jews of Banu Qurayzah.
For this reason, they have been included under this chapter.
The Jews, according to their nature, were always plotting to uproot the Muslims.
Therefore, it became necessary to cleanse Madinah of them, and this battle was fought, in which Allah purified Madinah from these evil-natured Jews.

Hadith Commentary:
➊
When, on the occasion of the Battle of Ahzab, Allah, the Exalted, sent the polytheists and disbelievers back in regret and failure, the Messenger of Allah (sallallahu alayhi wa sallam) said:
“Who will protect the honor and dignity of the Muslims?” Ka‘b ibn Malik (radi Allahu anhu), Abdullah ibn Rawahah (radi Allahu anhu), and Hassan ibn Thabit (radi Allahu anhu) stood up, so he (sallallahu alayhi wa sallam) selected Hassan (radi Allahu anhu) and said:
“Satirize them, the Holy Spirit, that is, Jibril (alayhis salam), will assist you.”
From this narration, it is also evident that the Messenger of Allah (sallallahu alayhi wa sallam) assigned this task to Hassan (radi Allahu anhu) on the occasion of the Battle of Qurayzah.
(Fath al-Bari: 7/520)
➋
Hassan (radi Allahu anhu) was chosen because he would become anxious about entering the battlefield; therefore, instead of defending with arrows and spears, he was tasked with defending through speech and eloquence, whereas Ka‘b ibn Malik (radi Allahu anhu) and Abdullah ibn Rawahah (radi Allahu anhu) were experienced in battle.
This is supported by the following incident: during the Battle of Ahzab, the women and children were kept in a fortress called Fari‘ with Hassan (radi Allahu anhu).
Coincidentally, a Jew entered the fortress, so Safiyyah bint Abdul-Muttalib (radi Allahu anha) said to Hassan (radi Allahu anhu) that this Jew is circling the fortress.
The Messenger of Allah (sallallahu alayhi wa sallam) and his noble Companions (radi Allahu anhum) are occupied, so you should go and kill him. Hassan (radi Allahu anhu) replied:
“You know that I am not a man for this task.”
After that, Safiyyah (radi Allahu anha) herself girded her waist, took a stick from the tent, and struck the Jew repeatedly with the stick until she finished him off.
Afterwards, she said to Hassan (radi Allahu anhu) that he is lying dead, so go and take his clothes and belongings.
Since he is a man, I did not remove his weapons.
Hassan (radi Allahu anhu) said:
“I have no need for his weapons or belongings.”
(Al-Sirah al-Nabawiyyah by Ibn Hisham: 2/239)
➌
In any case, in the aforementioned ahadith, there is mention of the Jews of Banu Qurayzah in one way or another; therefore, Imam Bukhari (rahimahullah) has narrated them under the chapter of the Battle of Banu Qurayzah.
➍
There is no doubt that the Jews of Madinah, according to their nature, continued to devise schemes to uproot the Muslims; therefore, it became necessary to purify Madinah Tayyibah from these serpents. Thus, the Messenger of Allah (sallallahu alayhi wa sallam) cleansed Madinah of these three tribes so that the Muslims could nurture Islam without fear or danger.