The Book of Forgetfulness (In Prayer)
13/79. Chapter:
Saying the takbir after the imam has said the taslim
Sunan an-Nasai
أَخْبَرَنَا بِشْرُ بْنُ خَالِدٍ الْعَسْكَرِيُّ، قَالَ حَدَّثَنَا يَحْيَى بْنُ آدَمَ، عَنْ سُفْيَانَ بْنِ عُيَيْنَةَ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنْ أَبِي مَعْبَدٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ إِنَّمَا كُنْتُ أَعْلَمُ انْقِضَاءَ صَلاَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم بِالتَّكْبِيرِ .
It was narrated that Ibn 'Abbas said: "I used to know that the prayer of the Messenger of Allah (ﷺ) ended by the takbir."
Reference : Sunan an-Nasa'i 1335In-book reference : Book 13, Hadith 157English translation : Vol. 2, Book 13, Hadith 1336