Sunan an-Nasa'i #887 · The Book of the Commencement of the Prayer

Sunan an-Nasa'iIt was narrated that Musa bin Umair Al-Anbari and Qais bin Sulaim Al-Anbari said
Sunan an-Nasa'i · Book 11 · The Book of the Commencement of the Prayer
Sunan an-Nasa'i · كتاب 11 · كتاب افتتاح الصلاة
"Alqamah bin Wa'il told us that his father said: "I saw the Messenger of Allah (ﷺ), when he was standing in prayer, holding his left hand with his right
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ مُوسَى بْنِ عُمَيْرٍ الْعَنْبَرِيِّ، وَقَيْسِ بْنِ سُلَيْمٍ الْعَنْبَرِيِّ، قَالاَ حَدَّثَنَا عَلْقَمَةُ بْنُ وَائِلٍ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم إِذَا كَانَ قَائِمًا فِي الصَّلاَةِ قَبَضَ بِيَمِينِهِ عَلَى شِمَالِهِ ‏.‏
Reference : Sunan an-Nasa'i 887In-book reference : Book 11, Hadith 12