Abdur-Rahman al-Muawl said: Abdullah bin Umar saw me playing with pebbles during prayer. When he finished his prayer, he forbade me (to do so) and said: Do as the Messenger ﷺ used to do. I asked him: How would the Messenger of Allah ﷺ do? He said: When he sat during the prayer (for reciting the tashahhud), he placed his right hand on his right thigh, and clenched all his fingers, and pointed with the finger which is adjacent to the thumb, and he placed his left hand on his left thigh.
Hadith Referenceسنن ابي داود / أبواب تفريع استفتاح الصلاة / 987
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم (580)