(14) The Book of Jumu'ah (Friday Prayer)
كتاب الجمعة
(43) Chapter: The Imam's Prayer After Jumu'ah
(43) صَلاَةُ الإِمَامِ بَعْدَ الْجُمُعَةِ
Sunan an-Nasa'i 1427 
It was narrated from Ibn 'Umar that:
The Messenger of Allah (ﷺ) would not pray after Jumu'ah until he had left, then he would pray two rak'ahs. (Sahih)
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ لاَ يُصَلِّي بَعْدَ الْجُمُعَةِ حَتَّى يَنْصَرِفَ فَيُصَلِّيَ رَكْعَتَيْنِ ‏.‏
Reference : Sunan an-Nasa'i 1427
In-book reference : Book 14, Hadith 64
English translation : Vol. 2, Book 14, Hadith 1428