Sunan an-Nasa'i 1656
سنن النسائي#1656Sahihأَخْبَرَنَا الْحَسَنُ بْنُ مُحَمَّدٍ، عَنْ حَجَّاجٍ، عَنِ ابْنِ جُرَيْجٍ، قَالَ أَخْبَرَنِي عُثْمَانُ بْنُ أَبِي سُلَيْمَانَ، أَنَّ أَبَا سَلَمَةَ، أَخْبَرَهُ أَنَّ عَائِشَةَ أَخْبَرَتْهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم لَمْ يَمُتْ حَتَّى كَانَ يُصَلِّي كَثِيرًا مِنْ صَلاَتِهِ وَهُوَ جَالِسٌ .
Abu Salamah narrated that Aishah told him:"The Prophet (ﷺ) did not die until most of his prayers were offered sitting down
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 20:59