Sunan an-Nasa'i 26
سنن النسائي#26Sahihأَخْبَرَنَا مُؤَمَّلُ بْنُ هِشَامٍ، قَالَ أَنْبَأَنَا إِسْمَاعِيلُ، قَالَ أَخْبَرَنَا شُعْبَةُ، عَنْ سُلَيْمَانَ، عَنْ أَبِي وَائِلٍ، عَنْ حُذَيْفَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَتَى سُبَاطَةَ قَوْمٍ فَبَالَ قَائِمًا .
It was narrated from Hudhifah that the Messenger of Allah (ﷺ)came to some people's garbage dump and urinated while standing
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 - Agreed Upon
In-book reference: 1:26