Sunan At-Tirmidhi

Ikrimah narrated that :Ibn Abbas was asked ahout Tayammum. He said: ""When Allah mentioned Wudu in His Book, He said: ""So wash your faces and your hands (forearms) up to the elbows."" And He said about Tayammum: ""And rub therewith your faces and hands"" And He said: ""And the male thief and the female thief; cut off their hands."" So the Sunnah for cutting is the two hands. So it is only the face and the hands, meaning, Tayammum