Yahya related to me from Malik from Abu'z Zinad from al-Araj from Abu Hurayra that the Messenger of Allah ﷺ said, "Even saying to your companion 'Listen' while the imam is giving the khutba on the day of jumua, is to speak foolishly."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا قُلْتَ لِصَاحِبِكَ أَنْصِتْ وَالإِمَامُ يَخْطُبُ يَوْمَ الْجُمُعَةِ فَقَدْ لَغَوْتَ