Mukhtasar Bukhari (Abridged) 520 — Remaining silent during the Friday

Abu Huraira (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) said: "If, on the day of Jumu'ah, while the Imam is delivering the sermon, you say to your companion, 'Be quiet,' then surely you have engaged in idle talk."