Tirmidhi

1:
The incident mentioned in this hadith of Umar radi Allahu anhu is a different incident from the one related to Ibn Mas'ud radi Allahu anhu. Here, it is only the incident of the missed (‘qada’) ‘Asr prayer, whereas there, it is the incident of making up (‘qada’) all the prayers from Dhuhr to Maghrib, and then making up all of them at the time of ‘Isha, which pertains to the following day. The Battle of Khandaq lasted for several days.

Explanation:
The Battle of the Trench (Khandaq) or the Battle of the Confederates (Ahzab) took place in the 5th year of Hijrah. Its detailed mention will come in its proper place. Although this narration does not explicitly state that the Prophet sallallahu alayhi wa sallam performed the prayer in congregation, it was his blessed habit to pray with the people in congregation. Therefore, this prayer too must have been performed by him in congregation. And in the narration of Isma‘ili, it is clearly mentioned that the Prophet sallallahu alayhi wa sallam performed the prayer with the Companions radi Allahu anhum.

In the explanation of this hadith, Allamah Shawkani rahimahullah says:
«(قوله ماكدت) لفظه كاد من افعال المقاربة فاذا قلت كادزيد يقوم فهم منه انه قارب القيام ولم يقم كما تقرر فى النحو والحديث يدل على وجوب قضاءالصلوٰة المتروكة لعذر الاشتغال بالقتال وقد وقع الخلاف فى سبب ترك النبى صلى الله عليه وسلم واصحابه لهذه الصلوٰة فقيل تركوها نسيانا وقيل شغلوا فلم يتمكنوا وهو الاقرب كما قال الحافظ وفي سنن النسائي عن ابي سعيد ان ذلك قبل ان ينزل الله فى صلوٰة الخوف فرجالاً اوركباناً وسياتي الحديث وقد استدل بهذا الحديث على وجوب الترتيب بين الفوائت المقضية والموداة الخ۔» [نيل الاوطار، ج2ص : 31]
That is, the word «كاد» is from the verbs of proximity (af‘al muqarabah). When you say «كاد زيد يقوم» (i.e., Zayd was about to stand), it will be understood that Zayd came close to standing but was not able to stand, as is established in the rules of grammar. Thus, in the narration, the purpose of the statement of Umar radi Allahu anhu is that he tried until the last moment to perform the ‘Asr prayer, but he was not able to perform it.

In the translation of the late Mawlana Waheeduz-Zaman, there is affirmation instead of negation, that he performed the ‘Asr prayer at the last moment. But the clarification of Imam Shawkani and the context of the hadith indicate that the translation of negation is correct, that he was not able to perform the ‘Asr prayer. That is why he himself says «فتوضاء للصلوٰة وتوضاء نالها» that you (the Prophet) also performed ablution (wudu) and we also performed ablution for it.

This hadith is evidence that the prayers which are missed due to engagement in battle or jihad, or for any other legitimate (shar‘i) reason, their making up (qada) is obligatory. And there is a difference of opinion as to why this prayer was missed by the Prophet sallallahu alayhi wa sallam and the noble Companions radi Allahu anhum. Some mention a certain reason, and others state that it happened due to the intensity and preoccupation of battle. And this seems to be correct, as Hafiz Ibn Hajar rahimahullah has said. And in the narration of Sa‘id radi Allahu anhu in al-Nasa’i, it is mentioned that this incident occurred before the revelation of the prayer of fear (salat al-khawf), when the ruling was that in the state of war, one should perform the prayer on foot or mounted, in whatever way possible. From this hadith, it is also established that it is obligatory to perform missed prayers in order.

Hadith Commentary:
(1)
In this hadith, the mention is of the missed ‘Asr prayer, whereas in a narration from Abu Sa‘id al-Khudri radi Allahu anhu, there is mention of both the Dhuhr and ‘Asr prayers being missed.
(Musnad Ahmad: 3/25)
And in the narration of Ibn Mas‘ud radi Allahu anhu, it is stated that during the Battle of the Trench (Ghazwah Khandaq), four prayers were missed.
(Al-Sunan al-Kubra lil-Bayhaqi: 4031)
The commentators have reconciled these differing narrations in the following two ways:
➊ The narration of Sahih al-Bukhari is given preference, and the remaining narrations are considered less preferred.
This explanation is supported by the narration of ‘Ali radi Allahu anhu, in which he says that the disbelievers of Quraysh did not allow us to perform the middle prayer (salat al-wusta), i.e., the ‘Asr prayer, during the Battle of the Trench.
(Sahih Muslim, al-Masajid, Hadith: 1420(627))
➋ During the Battle of the Trench, multiple incidents occurred: in some, one prayer was missed, and in others, more than one prayer is mentioned as missed.
This position is supported by the fact that in the narrations from Abu Sa‘id and Ibn Mas‘ud radi Allahu anhum, there is no mention of ‘Umar radi Allahu anhu, and in these narrations, it is stated that the missed prayers were performed after the time of Maghrib had passed, whereas according to the hadith of Sahih al-Bukhari, the ‘Asr prayer was performed after sunset.
(Fath al-Bari: 92/2)
(2)
In this hadith, there is no explicit mention of the missed prayers being performed in congregation; however, in the narration of Isma‘ili, it is clarified that the Messenger of Allah sallallahu alayhi wa sallam led us in the ‘Asr prayer.
Additionally, in the narration from Abu Sa‘id al-Khudri radi Allahu anhu, it is explicitly stated that the iqamah was called for the prayers, and then he (the Prophet sallallahu alayhi wa sallam) led them as he would lead them in their proper times.
(Sunan al-Nasa’i, al-Adhan, Hadith: 662)
In the narration of Ibn Mas‘ud radi Allahu anhu as well, there is mention of congregation.
(Musnad Ahmad: 1/375)
It should be noted that the prayers of the Messenger of Allah sallallahu alayhi wa sallam and the noble Companions radi Allahu anhum were missed because the rulings of Salat al-Khawf (prayer of fear) had not yet been revealed.
(Sunan al-Nasa’i, al-Adhan, Hadith: 662)