Sunan an-Nasa'i 888
سنن النسائي#888Hasanأَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، قَالَ حَدَّثَنَا هُشَيْمٌ، عَنِ الْحَجَّاجِ بْنِ أَبِي زَيْنَبَ، قَالَ سَمِعْتُ أَبَا عُثْمَانَ، يُحَدِّثُ عَنِ ابْنِ مَسْعُودٍ، قَالَ رَآنِي النَّبِيُّ صلى الله عليه وسلم وَقَدْ وَضَعْتُ شِمَالِي عَلَى يَمِينِي فِي الصَّلاَةِ فَأَخَذَ بِيَمِينِي فَوَضَعَهَا عَلَى شِمَالِي .
It was narrated that Al Hajjaj bin Abi Zainab said:X"I heard Abu Uthman narrate that Ibn Mas'ud said: 'The Prophet (ﷺ) saw me when I had placed my left hand on my right in prayer. He took hold of my right hand and placed it on my left
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: 11:13