Sunan an-Nasa'i 236
سنن النسائي#236Sahihأَخْبَرَنَا يَحْيَى بْنُ مُوسَى، عَنْ سُفْيَانَ، عَنْ عَمْرٍو، عَنْ جَابِرِ بْنِ زَيْدٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ أَخْبَرَتْنِي خَالَتِي، مَيْمُونَةُ أَنَّهَا كَانَتْ تَغْتَسِلُ وَرَسُولُ اللَّهِ صلى الله عليه وسلم مِنْ إِنَاءٍ وَاحِدٍ .
It was narrated that Ibn 'Abbas said:"My maternal aunt Maimunah told me that she and the Messenger of Allah (ﷺ) used to perform Ghusl from one vessel
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: 1:237