(122) باب وَضْعِ الْيُمْنَى عَلَى الْيُسْرَى فِي الصَّلاَةِ
Narrated Abdullah ibn Mas'ud:
AbuUthman an-Nahdi said: When Ibn Mas'ud prayed he placed his left hand on the right. The Prophet (ﷺ) saw him and placed his right hand on his left one.
Reference: Sunan Abi Dawud 755
In-book reference: Book 2, Hadith 365
English translation: Book 3, Hadith 754