(14) The Book of Jumu'ah (Friday Prayer)
كتاب الجمعة
(22) Chapter: Listening Attentively To The Khutbah On Friday
(22) بَابُ الإِنْصَاتِ لِلْخُطْبَةِ يَوْمَ الْجُمُعَةِ
Sunan an-Nasa'i 1401 
It was narrated from Abu Hurairah that:
The Messenger of Allah (ﷺ) said: "Whoever says to his companion on Friday, when the imam is delivering the khutbah: 'Listen attentively,' has engaged in idle talk."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ عُقَيْلٍ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ قَالَ لِصَاحِبِهِ يَوْمَ الْجُمُعَةِ وَالإِمَامُ يَخْطُبُ أَنْصِتْ فَقَدْ لَغَا ‏"‏ ‏.‏
Grade :  Sahih (Darussalam)
Reference : Sunan an-Nasa'i 1401
In-book reference : Book 14, Hadith 38
English translation : Vol. 2, Book 14, Hadith 1402