Hazrat Ali bin Abdur Rahman says that Abdullah bin Umar (may Allah be pleased with them) saw me playing with pebbles during prayer. When I finished the prayer, he forbade me and said: Do as the Messenger of Allah (peace and blessings be upon him) used to do. I asked: How did he do? He said: When he (peace and blessings be upon him) sat in prayer, he would place his right palm on his right thigh and close all the fingers, and point with the index finger, and place the left palm on the left thigh, and he (peace and blessings be upon him) used to do like this.