Sunan Ibn Majah
1110
Sahih+3

It was narrated from Abu Hurairah that the Prophet (ﷺ) said:“If you say to your companions: ‘Be quiet’ on a Friday while the Imam is delivering the sermon, you have engaged in Laghw (idle talk or behaviour).”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi