Sunan an-Nasa'i, Volume 1, Book 10, Hadith 786 (DarusSalam) ⓘ
It was narrated that Anas said: "In the last prayer that the Messenger of Allah prayed with the people, he prayed wrapped up in a single garment, behind Abu Bakr."
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 .
also referenced under: Hadith 785 (Reference) & Book 10, Hadith 9 (In-Book)