The Book of Leading the Prayer (Al-Imamah)
10/8. Chapter:
The prayer of an Imam behind a man of his people
Sunan an-Nasai
أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنَا حُمَيْدٌ، عَنْ أَنَسٍ، قَالَ آخِرُ صَلاَةٍ صَلاَّهَا رَسُولُ اللَّهِ صلى الله عليه وسلم مَعَ الْقَوْمِ صَلَّى فِي ثَوْبٍ وَاحِدٍ مُتَوَشِّحًا خَلْفَ أَبِي بَكْرٍ .
It was narrated that Anas said: "In the last prayer that the Messenger of Allah(ﷺ) prayed with the people, he prayed wrapped up in a single garment, behind Abu Bakr."
Reference : Sunan an-Nasa'i 785In-book reference : Book 10, Hadith 9English translation : Vol. 1, Book 10, Hadith 786