Bukhari

Hadith Commentary:
(1)
In one narration, it is mentioned that the Messenger of Allah sallallahu alayhi wa sallam supplicated for goodness and blessings for the Muhajirun and Ansar. He made these supplications upon the expression of the following sentiments by the noble Companions radi Allahu anhum: "We are those who pledged allegiance to the Messenger of Allah sallallahu alayhi wa sallam upon his hand that we will remain steadfast on the path of Islam as long as we live." (Sahih al-Bukhari, al-Maghazi, Hadith: 4100)

(2)
It should be noted that the noble Companions radi Allahu anhum dug the trench during severe cold. At that time, they did not even have slaves or the like who could perform the duty of digging the trench in their place. (Sahih al-Bukhari, al-Maghazi, Hadith: 4099)

(3)
Although living a life of comfort, ease, and luxury in this world is not forbidden or unlawful, the station of Allah’s special servants is that, instead of living a life of indulgence and luxury in this world, they keep their gaze fixed on the delights and pleasures of the Hereafter. This is the very meaning of "O Allah, there is no life except the life of the Hereafter." Thus, when the Messenger of Allah sallallahu alayhi wa sallam dispatched Mu'adh ibn Jabal radi Allahu anhu to Yemen, he advised him: "O Mu'adh! Refrain from seeking comfort and luxury, for Allah’s special servants are not seekers of comfort and luxury." (Musnad Ahmad: 243/5, and al-Sahihah of al-Albani, Hadith: 353)

(4)
The commentator Ibn Munir states that the reason why the majority of people are at a loss despite having health and free time is that they have preferred the life of this world over the life of the Hereafter. Therefore, the luxury and indulgence in which they are engrossed has no real substance; rather, it is like bubbles on water. The true life is the one they have neglected, and whoever has ruined his life of the Hereafter is, in reality, the one who is in loss and deprivation. (al-Mutawari, p. 391)

Hadith Commentary:
When he saw the present hardships of the Ansar and the Muhajirin, he said this to console them, that true comfort is the comfort of the Hereafter.
It is necessary for a believer to be patient over the hardships of this world.
The Battle of Khandaq (the Trench) occurred during a time of severe hardship.

Hadith Commentary:
➊
During the Battle of the Trench (Ghazwah Khandaq), the weather in Madinah was extremely cold. When the Messenger of Allah (sallallahu alayhi wa sallam) saw the hardship of the Ansar and Muhajirun while digging the trench, he said to comfort them:
“True rest will be attained on the Day of the Hereafter, and bearing the hardships of this world with patience is the hallmark of a believer.”
The Messenger of Allah (sallallahu alayhi wa sallam) himself participated in digging the trench to encourage his noble Companions (radi Allahu anhum ajma‘in) towards reward, and along with him, the other Companions (radi Allahu anhum ajma‘in) also took part in this task, because at that time they did not have servants or slaves to do the work of digging the trench.

➋
It should be noted that the suggestion to dig a trench around Madinah was given by Salman al-Farisi (radi Allahu anhu), which the Messenger of Allah (sallallahu alayhi wa sallam) deemed appropriate.
(Fath al-Bari: 7/491)

Hadith Commentary:
This is the incident of the Battle of Ahzab, in which the Muslims defended themselves from within the city against the armies of the Arab disbelievers, who were great in number. A trench was dug around the outskirts of the city for its protection, which is why it is also called the Battle of the Trench (Khandaq). A detailed account will follow later. In this, there is a virtue for the Ansar and the Muhajirun, and this is precisely the subject of the chapter heading.

Hadith Commentary:
➊
This incident pertains to the Battle of the Trench (Ghazwah Khandaq), when the tribes of Madinah attacked and a trench was dug for the protection of the inner city.
Both the Ansar and the Muhajirun participated in digging this trench.
At that time, the Messenger of Allah (sallallahu alayhi wa sallam) made abundant supplications for the Ansar and the Muhajirun.

➋
In these three narrations, different words of the Messenger of Allah (sallallahu alayhi wa sallam) have been reported.
He made different supplications on different occasions; thus, sometimes he said:
"Forgive them."
At times, he supplicated for their rectification, and at other times, he prayed for mercy and kindness upon them.
Allah, the Exalted, honored all these supplications with acceptance.
(Fath al-Bari: 7/150)

Explanation:
1:
The author of Tuhfat al-Ahwadhi has titled this hadith under (Chapter: The Virtues of Sahl ibn Sa'd),
and this is appropriate,
because this hadith has no connection whatsoever with Abu Musa radi Allahu anhu,
and in it is mentioned the virtue of all the Muhajirun and Ansar Companions,
who specifically participated in the digging of the trench,
radi Allahu anhum ajma'in.