Yahya related to me from Malik from Abu'z Zinad from al-Araj from
Abu Hurayra that the Messenger of Allah, may Allah bless him and grant
him peace, said, "Even saying to your companion 'Listen' while the
imam is giving the khutba on the day of jumua, is to speak foolishly."
Muwatta Malik Book 5, Hadith 6