Al-A'raf 7:204 وَإِذَا قُرِئَ ٱلۡقُرۡءَانُ فَٱسۡتَمِعُواْ لَهُۥ وَأَنصِتُواْ لَعَلَّكُمۡ تُرۡحَمُونَ So, when the Qur’an is recited, listen to it, and be silent that you may receive mercy. [i.e. during the compulsory congregational prayers when the Imam (of a mosque) is leading the prayer (except Surat Al-Fatihah), and also when he is delivering the Friday-prayer Khutbah]. (Tafsir At-Tabari).