It wasnarrated from Abu Hurairah that the Prophet (ﷺ) said:
"Ifyou sayto your companions: 'Be quiet' on a Friday while the Imam isdelivering the sermon, you have engaged in Laghw (idle talk orbehaviour)." (RU)
English reference (RU): Vol. 1, Book 5, Hadith 1110 (RU)
Arabic reference (RU): Book 5, Hadith 1164 (RU)