Mu'jam al-Saghir

553. Commentary:
This and other ahadith are clear evidence that congregational prayer is obligatory. Everyone knows that even in times of fear, the prayer of fear (salat al-khawf) is legislated to be performed in congregation. And for those with valid excuses, it is established from the evidences that permission is indeed granted to remain behind from the congregation, but they will be deprived of this virtue. Shah Waliullah has written in Hujjatullah al-Baligha that the reason for not granting concession to Abdullah ibn Umm Maktum was perhaps because his question pertained to the original ruling (azimah). Whereas the Noble Prophet (sallallahu alayhi wa sallam) inaugurated the prayer place of ‘Itban ibn Malik (radi Allahu anhu) by going to his house. And in the aforementioned hadith of Ibn Abbas (radi Allahu anhu), there is also an exception for a legal excuse such as fear or illness.

Commentary:
(1)
Our esteemed scholar, rahimahullah, writes regarding the aforementioned hadith that this narration is weak in its chain of transmission, but the narration in Sahih Muslim (653) suffices for it.
For details, refer to the authentication and referencing of the hadith.
Other scholars have also declared it authentic.
For details, see: (al-Mawsu‘ah al-Hadithiyyah, Musnad al-Imam Ahmad: 255, 244, 243/24)
This hadith clarifies the importance of congregational prayer (salah bi’l-jama‘ah), as the Messenger of Allah (sallallahu alayhi wa sallam) did not grant permission to Ibn Umm Maktum (radi Allahu anhu) to pray without the congregation, even though he had several valid excuses:

(➊)
He was elderly.

(➋)
He was blind.

(➌)
His house was far.

(➍)
There was no one in his household who could consistently fulfill the duty of bringing him to the mosque.

(➎)
The person who did bring him to the mosque did not serve him according to his wishes, but rather prioritized his own convenience. (WALAYSA LI QĀ’IDUN YULĀWIMUNĪ)
“There is no one to bring me according to my wishes”—this is what it means.

(➏)
There was a low-lying area between his house and the mosque in which water would collect during rainfall.
For further details, see:
(Salat al-Jama‘ah, Ahammiyyatuha wa Fadluha, authored by Dr. Fazl Ilahi.)

(3)
The Messenger of Allah (sallallahu alayhi wa sallam) did not permit Ibn Umm Maktum to remain behind from the congregation so that he would attain the maximum reward.
The purpose was encouragement; otherwise, if a blind person finds it difficult to come to the mosque, it is permissible for him to pray at home.
As the Prophet (sallallahu alayhi wa sallam) had granted permission to ‘Itban ibn Malik (radi Allahu anhu).
See: (Sunan Ibn Majah, Hadith: 754)

(4)
The Messenger of Allah (sallallahu alayhi wa sallam) asked him regarding the adhan—whether he could hear it or not. This indicates that a person residing far from the settlement, where the adhan is generally not heard, may perform the prayer there.