I heard the Prophet ﷺ say, "If you say to your companion while the imam is delivering the sermon, 'Be quiet,' you have engaged in idle talk."Ibn Jurayj said, Ibn Shihab informed me from Umar bin Abdul-Aziz, from Ibrahim bin Abdullah bin Qariz, from Abu Hurairah, from the Prophet ﷺ, a similar report.
حدثنا عبد الرزاق حدثنا ابن جريج ومالك عن ابن شهاب عن ابن المسيب
سمعت النبي ﷺ يقول إذا قلت لصاحبك والإمام يخطب أنصت فقد لغوت قال ابن جريج وأخبرني ابن شهاب عن عمر بن عبد العزيز عن إبراهيم بن عبد الله بن قارظ عن أبي هريرة عن النبي ﷺ مثله
[Shakir: 7750] Its isnad is sahih. It is a repeat of 7672, in one of its two chains, and here he added the narration of Abdul-Razzaq from Malik, from Zuhri.[Shakir: 7751] Its isnad is sahih. It is a repeat of 7672, in its other chain.