وَعَن سهل بن سعد
قَالَ: كَانَ النَّاسُ يُؤْمَرُونَ أَنْ يَضَعَ الرَّجُلُ الْيَدَ الْيُمْنَى عَلَى ذِرَاعِهِ الْيُسْرَى فِي الصَّلَاةِ
The people received command that a man should place the right hand on the left forearm in prayer.
Mishkat al-Masabih 748, Book 5, Prayer, Hadith 226. 1 min read