Ibn Majah

1؎: In Musnad Ahmad and Sunan Abu Dawud, it is narrated from Ali radi Allahu anhu that whoever sits near the imam but engages in idle activity, does not listen to the sermon (khutbah), and does not remain silent, then upon him will be a portion of the burden (of sin). And whoever says, “Be quiet,” has engaged in idle talk, and whoever engages in idle talk, his Friday (Jumu‘ah) is not valid. Ali radi Allahu anhu says that this is exactly what I heard from the Prophet sallallahu alayhi wa sallam. The summary of the ahadith of this chapter is that for the one who comes to perform Jumu‘ah, all kinds of religious and worldly conversation are prohibited during the sermon, including remembrance (dhikr) and supplications (adhkar). Similarly, mutual advice and exhortation are also included. However, due to necessity, need, or a Shari‘ah-based benefit, the imam may address the listeners, as is established from several ahadith of the Messenger of Allah sallallahu alayhi wa sallam. In fact, in the following hadith, the Prophet sallallahu alayhi wa sallam instructed Sulaik Ghatafani radi Allahu anhu to perform two rak‘ahs. Also, the listeners may, in following the imam during the sermon, send salutations (salat wa salam) upon him and say amin to his supplications, but it should be clear that this must not cause any disturbance in listening to the sermon or in the respect of the mosque.