Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: It is enough to count as idle talk that, on Friday, once the imam has come out, you say to your companion: "Be quiet!"
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 3135