Sunan an-Nasa'i 24
سنن النسائي#24Sahihأَخْبَرَنَا يَحْيَى بْنُ دُرُسْتَ، قَالَ أَنْبَأَنَا أَبُو إِسْمَاعِيلَ، - وَهُوَ الْقَنَّادُ - قَالَ حَدَّثَنِي يَحْيَى بْنُ أَبِي كَثِيرٍ، أَنَّ عَبْدَ اللَّهِ بْنَ أَبِي قَتَادَةَ، حَدَّثَهُ عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِذَا بَالَ أَحَدُكُمْ فَلاَ يَأْخُذْ ذَكَرَهُ بِيَمِينِهِ " .
It was narrated from 'Abdullah bin Abi Qatadah, from his father, that the Messenger of Allah (ﷺ said:"When any one of you urinates, let him not hold his penis in his right hand)
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: 1:24