It was narrated from 'Abdullah bin Ibrahim bin Qariz and Sa'eed bin Al-Musayyab that:
Abu Hurairah said: "I heard the Messenger of Allah (ﷺ) say: 'If you say to your companion: Listen attentively on a Friday when the Imam is delivering the khutbah, then you have engaged in idle talk.'" (AR)
App reference (AR): Book 14, Hadith 39 (AR)
English reference (AR): Vol. 2, Book 14, Hadith 1403 (AR)
Arabic reference (AR): Book 14, Hadith 1413 (AR)