Sunan an-Nasa'i 1266

Ali bin Abdur-Rahman said:"I prayed beside Ibn Umar and I turned over the pebbles. Ibn Umar said to me: 'Do not turn over the pebbles, for turning over the pebbles comes from Shaitan. Do what I saw the Messenger of Allah (ﷺ) do.' I said: 'What did you see the Messenger of Allah (ﷺ) do?' He said; 'This'- and he held his right foot upright and lay his left foot on the ground, and placed his right hand on his right thigh and his left hand on his left thigh, and pointed with his forefinger