Bukhari

Hadith Commentary:
1.
Hafiz Ibn Hajar rahimahullah writes:
It is permissible to send spies to gather information about the enemy before launching a military expedition, so that the enemy does not take advantage of the Muslims’ heedlessness and cause them harm.
(Fath al-Bari: 8/66)
2.
Some narrations indicate that the Messenger of Allah sallallahu alayhi wa sallam sent Hudhayfah radi Allahu anhu for espionage.
This narration is not contrary to that, because Zubayr radi Allahu anhu was assigned to bring news about Banu Qurayzah, whereas Hudhayfah radi Allahu anhu was sent to gather information about the conditions of the disbelievers of Quraysh. Furthermore, Zubayr radi Allahu anhu did not give the same answer three times at one place, rather, this answer was given on three different occasions.

Hadith Commentary:
By "the day of Banu Qurayzah" is meant the day when, during the Battle of the Trench (Khandaq), the Messenger of Allah (sallallahu alayhi wa sallam) instructed for news to be brought regarding Banu Qurayzah. It does not refer to the day when Banu Qurayzah were besieged and fighting with them began, because that battle took place after the Battle of the Trench and continued for several days.

The relevance to the chapter is clear: the Messenger of Allah (sallallahu alayhi wa sallam) sent a single person, Zubair (radi Allahu anhu), to bring news, and the report of one person was considered reliable.

Hadith Commentary:
➊
The "Day of Banu Qurayzah" refers to the day when, on the occasion of the Battle of the Trench (Ghazwah Khandaq), the Messenger of Allah (sallallahu alayhi wa sallam) instructed that information about Banu Qurayzah be brought.
This does not refer to the day of the siege of Banu Qurayzah itself, because that siege took place after the Battle of the Trench and continued for several days.
Eventually, they descended from their fortresses based on the decision of Sa'd ibn Mu'adh (radi Allahu anhu).
Then this siege reached its logical conclusion.

➋
The purpose of Imam al-Bukhari (rahimahullah) is to show that the Messenger of Allah (sallallahu alayhi wa sallam) sent only Zubair (radi Allahu anhu) to bring information about the enemies:
Then the Prophet (sallallahu alayhi wa sallam) relied upon his report.
From this, it is understood that a solitary report (khabar wahid) is authoritative, provided it is narrated by a trustworthy transmitter.

Hadith Commentary:
In some narrations, it is mentioned that Hudhayfah (radi Allahu anhu) went to assess the situation. There is no contradiction in these narrations because Hudhayfah (radi Allahu anhu) went to bring news about the Quraysh. It was the winter season, and Hudhayfah (radi Allahu anhu) was shivering from the cold, so the Messenger of Allah (sallallahu alayhi wa sallam) embraced him to give him warmth. As for Zubayr (radi Allahu anhu), he was sent to bring news about Banu Qurayzah because they had a treaty with the Messenger of Allah (sallallahu alayhi wa sallam), but they broke the covenant and committed treachery, conspiring with the Quraysh and preparing to fight against the Muslims.

In any case, the Messenger of Allah (sallallahu alayhi wa sallam) sent both of these companions to bring news about both groups.
(Fath al-Bari: 7/508)

Hadith Commentary:
➊
The person who is sent to gather information about the enemy is called "Talī‘at al-Jaysh" (the vanguard of the army).
According to one hadith, it is prohibited for a person to travel alone.
There could have been a misconception that even for espionage, a single person cannot be sent.
Imam Bukhari rahimahullah has presented the aforementioned chapter heading and hadith to remove this misconception.
Since secrecy is maintained in espionage, it is appropriate that only one person be chosen for this task.
It is not appropriate to apply this to general travel, nor is it correct to derive the ruling of traveling alone from this hadith.
The prohibition regarding traveling alone remains in its place.

➋
The Jews of Madinah, specifically the Banu Qurayzah tribe, had a treaty with the Messenger of Allah sallallahu alayhi wa sallam that they would jointly defend Madinah Tayyibah.
When the disbelievers of Quraysh attacked Madinah Tayyibah, Banu Qurayzah broke their covenant and sided with them.
When the situation became critical, the Messenger of Allah sallallahu alayhi wa sallam called upon people to gather information about their situation.
Zubair radi Allahu anhu stepped forward and took on this heavy responsibility, so the Messenger of Allah sallallahu alayhi wa sallam, pleased with him, said:
"Zubair ibn al-Awwam is my sincere companion."

Chapter of Sahih Bukhari Hadith Number: 2997: «بَابُ السَّيْرِ وَحْدَهُ:»
Relevance between the Chapter Heading and the Hadith:
Imam Bukhari rahimahullah has established the relevance between the chapter heading (tarjamat al-bab) and the hadith in this way: that Sayyiduna Zubair radi Allahu anhu went alone to bring news of the disbelievers. This incident is from the Battle of Khandaq, which is also called the Battle of Ahzab. Now, the relevance between the chapter heading and the hadith is as follows: necessarily, when Sayyiduna Zubair radi Allahu anhu presented himself and said, “I am present,” meaning to bring news of the disbelievers, then he must have traveled for this task, and he was alone. From here, the connection between the chapter heading and the hadith is established.

Imam Isma‘ili has raised an objection regarding the mention of this chapter and says:
«لا أعلم هذا الحديث كيف يدخل فى هذا الباب؟»
“I do not know how this hadith (the one about Sayyiduna Zubair radi Allahu anhu) fits the meaning of the chapter.”
And Ibn al-Munir rahimahullah has also supported this view, saying that it is possible someone else was with Sayyiduna Zubair radi Allahu anhu on the journey. However, Hafiz Ibn Hajar rahimahullah, responding to this, says:
«قلت: لكن قد ورد من وجه آخر ما يدل على ذالك و فيه قلت يا أبت رأيتك تختلف، فقال: قال رسول الله صلى الله عليه وسلم: من ياتيني بخبر قريظة فانطلقت.» [فتح الباري، ج 6، ص: 170]
Here, there is no mention (of whether Sayyiduna Zubair radi Allahu anhu was alone or if someone else was with him), but this very incident is mentioned in «مناقب زبير», from which it is known that he radi Allahu anhu undertook this journey entirely alone. He himself said: I saw my father several times going to and coming from Banu Qurayza, so I asked him: “You are repeatedly going to Banu Qurayza, what is the matter?” He replied that the Prophet sallallahu alayhi wa sallam had said to us, “Who will bring news of Banu Qurayza?” so I set out. From this narration, it is clearly established that he traveled alone. Even clearer wording is found in Sunan al-Nasa’i, after which there remains no room for interpretation.

Wahb ibn Kaysan rahimahullah mentions this incident:
«أشهد سمعت جابر بن عبد الله . . . . . فلم يذهب أحد، فذهب الزبير.» [سنن النسائي، ج 5، ص: 262]
“I bear witness that I heard from Sayyiduna Jabir ibn Abdullah radi Allahu anhu, so no one went with him, then Sayyiduna Zubair radi Allahu anhu himself (alone) went.”
Benefit:
Imam Muhallab rahimahullah says:
“The wisdom in prohibiting traveling alone at night is that nighttime is when the devils spread out, cause harm, and cast whispers into people’s hearts. For this reason, the Prophet sallallahu alayhi wa sallam used to prohibit letting children go out at night. However, it is not forbidden (haram); if there is no necessity, it is disliked (makruh). If a travel companion is present, it is preferable and better.” [شرح ابن بطل، ج 5، ص: 155]

Hadith Commentary:
Some have said that the followers of ‘Isa (alayhis salam) are called Hawariyyun because they used to wear white clothing.
Qatadah said: Hawari is one who is worthy of succession (khilafah) or a minister endowed with wisdom and prudence.
From this hadith, Imam Bukhari (rahimahullah) established the purpose of the chapter in such a way that Zubair (radi Allahu anhu) alone went to bring news of the disbelievers.
This pertains to the Battle of Khandaq, which is also called the Battle of Ahzab.
Some details of this are mentioned in Surah Ahzab, and it will be mentioned in the Book of Maghazi.

Hadith Commentary:
In the Noble Qur’an, the term "Hawari" has been used for the devoted supporters of Prophet ‘Isa (alayhis salam). Although, in general, all the noble Companions (radi Allahu anhum) were devoted supporters of the Messenger of Allah (sallallahu alayhi wa sallam), due to certain particular distinctions, the Prophet (sallallahu alayhi wa sallam) specifically bestowed this title upon Hazrat Zubair (radi Allahu anhu).

Hadith Commentary:
In one narration, the reason for these words of praise is mentioned: On the occasion of the Battle of Ahzab, the Messenger of Allah (sallallahu alayhi wa sallam) said, "Who will spy on the polytheists for me and inform me of their situation?" Zubair (radi Allahu anhu) said, "O Messenger of Allah (sallallahu alayhi wa sallam)! I am present for this task." When you expressed this desire three times, Zubair (radi Allahu anhu) gave the same reply each time, saying that he would find out the evil intentions of the polytheists and convey them to you. At that time, you uttered these words of praise. (Sahih al-Bukhari, al-Jihad, Hadith: 2847)

There is no doubt that helping at such a time holds greater importance compared to other times, because to find out someone's situation by infiltrating among them is to put one's own life in danger.

Hadith Commentary:
Vocabulary of the Hadith:
(2)
Hawari:
Pure white,
that is, a sincere companion,
a special helper.

Benefits and Issues:
On the occasion of the Battle of the Trench (Ghazwah Khandaq), when the Prophet (sallallahu alayhi wa sallam) learned of the treachery and betrayal of Banu Qurayzah, he wished to send someone to obtain accurate information about them.
When Zubair (radi Allahu anhu) immediately volunteered himself for this task,
there was no longer any need to put anyone else forward.

Explanation:
1:
On the occasion of the Battle of Ahzab, when the Prophet sallallahu alayhi wa sallam sought to learn about the activities of the disbelievers, he made this announcement: “Who will inform me about the condition of the disbelievers?” He said this three times, and on all three occasions, no one responded except Zubair radi Allahu anhu.
It was on this occasion that the Prophet sallallahu alayhi wa sallam said regarding Zubair radi Allahu anhu: (Indeed, every Prophet has a disciple, and my disciple is Az-Zubair ibn al-Awwam).
Also remember that Zubair ibn al-Awwam was the son of the Prophet’s sallallahu alayhi wa sallam paternal aunt, Safiyyah radi Allahu anha, and he was married to Asma bint Abi Bakr radi Allahu anhum, the elder sister of Umm al-Mu’minin Aisha radi Allahu anha.

Commentary:
(1)
The campaign against Banu Qurayzah began immediately after the Battle of the Trench (Khandaq); in this way, both expeditions are as if they are one and the same. Here, "the day of Banu Qurayzah" refers to an incident from one of the days of the Battle of Ahzab.

(2)
By "Hawari" is meant a devoted companion. Just as the companions (Hawariyyun) of Isa (alayhis salam) said:
﴿نَحْنُ اَنْصَارُ الله﴾ (As-Saff: 14)
"We are the helpers of Allah (in His religion)."

(3)
From this, the greatness and status of Zubair (radi Allahu anhu) becomes evident, as the Prophet (sallallahu alayhi wa sallam) counted him among his closest companions.

Benefit:
From this hadith, the virtue of Sayyiduna Zubair bin al-Awwam (radi Allahu anhu) is established. This hadith also shows that an important matter should be repeated three times.