Sunan an-Nasa'i, Volume 3, Book 21, Hadith 1919 (DarusSalam) ⓘ
It was narrated that Abu Hurairah and Abu Sa'eed said: "We never saw the Messenger of Allah attend any funeral where he sat down until (the body) was placed (in the grave)."
أَخْبَرَنَا يُوسُفُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا حَجَّاجٌ، عَنِ ابْنِ جُرَيْجٍ، عَنِ ابْنِ عَجْلاَنَ، عَنْ سَعِيدٍ، عَنْ أَبِي هُرَيْرَةَ، وَأَبِي، سَعِيدٍ قَالاَ مَا رَأَيْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم شَهِدَ جَنَازَةً قَطُّ فَجَلَسَ حَتَّى تُوضَعَ .
also referenced under: Hadith 1918 (Reference) & Book 21, Hadith 101 (In-Book)