أَخْبَرَنَا 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 (PBUH) 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.'" Translation Not Available
Book Ref: Sunan An Nisai Book 11 Hadith 888
Web Ref: Sunan An Nisai Vol 2 Book 11 Hadith 889