(237) باب الْكَلاَمِ وَالإِمَامُ يَخْطُبُ
Abu Hurairah reported the Messenger of Allah (ﷺ) as saying:
When you tell (your brother on Friday) to be silent while the imam is giving the sermon you are guilty of idle talk.
Reference: Sunan Abi Dawud 1112
In-book reference: Book 2, Hadith 723
English translation: Book 2, Hadith 1107