13- وبه: أن رسول الله صلى الله عليه وسلم قال: ”إذا قلت لصاحبك: أنصت، والإمام يخطب، فقد لغوت.“
And with the same chain of narration, it is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When you say to your companion 'Be quiet,' while the Imam is delivering the (Friday) sermon, then you have engaged in idle (vain) talk."
Related hadith on this topic