wa alaykum salam wa rahmatuLlahi wa barakatuHu,

The congregational prayer is a communal obligation according to the relied-upon opinion in the Shafi’i School. This is a point on which Imams An-Nawawi and Ar-Rafi’i differ. In Fath al-Aziz v. 2, p. 141, Rafi’i considered it a sunnah; and in Rawdah v. 1, p. 520, Nawawi considered it a communal obligation (fard Kifayah). It is most virtuous that one performs the congregational prayer in a mosque; while it is also achieved by performing it with another in another place, like with one’s family at home for example. Whether or not we consider the congregational prayer an obligation or recommended, the valid excuses for omitting it are in fact only a few. For instance, a severe weather condition, an illness, fearing for one’s person or property, one has eaten something with an offensive odor, one is eating or drinking, one does not have proper clothing to wear to the mosque, etc. (Rawdat al-Talibin v. 1, p. 520-22, 525)

And Allah knows best.

Shafiifiqh.com Fatwa Dept.