After Ibn al-Qayyim, in his work Kitāb al-Ṣalāh, surveyed the scholars’ opinions and the proofs they relied upon, he concluded: “Whoever contemplates the Sunnah with proper reflection will realize that performing the prayer in the mosques is an individual obligation, except when there is an impediment that likewise permits one to miss Friday and congregational prayer. In this all the aḥādīth and reports concur … What we hold before Allah is that no one may stay behind from the congregation in the mosque unless he has a valid excuse.”
Points derived from the ḥadīth:
1- Congregational prayer is an individual duty for adult men.
2- Whoever abandons the congregation without excuse is sinful and liable to punishment.
3- Preventing harm takes precedence over procuring benefit: the Prophet refrained from punishing them in this manner only out of fear of harming those who did not deserve punishment.
4- The hypocrites sought nothing from their worship but show and reputation, for they did not come to the prayer except when people could see them.
5- The particular virtue of the ʿIshāʾ and Fajr prayers.
6- The heaviness of the Fajr and ʿIshāʾ prayers refers to performing them in congregation, as indicated by the context; they felt heavy because the motives to stay away from them were strong and the factors urging attendance were weak.