Sunan an-Nasa'i 226
سنن النسائي#226Sahihأَخْبَرَنَا مُحَمَّدُ بْنُ عُبَيْدٍ، قَالَ حَدَّثَنَا يَحْيَى بْنُ زَكَرِيَّا بْنِ أَبِي زَائِدَةَ، عَنْ مُوسَى الْجُهَنِيِّ، قَالَ أُتِيَ مُجَاهِدٌ بِقَدَحٍ حَزَرْتُهُ ثَمَانِيَةَ أَرْطَالٍ فَقَالَ حَدَّثَتْنِي عَائِشَةُ رضى الله عنها أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَغْتَسِلُ بِمِثْلِ هَذَا .
It was narrated that Musa Al-Juhani said:"A vessel was brought to Mujahid, which I estimated to be eight Ratls, and he said: 'Aishah told me that the Messenger of Allah (ﷺ) used to perform Ghusl using such a 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:
In-book reference: 1:227