Sunan At-Tirmidhi

Hilal bin Yasar said:""Ziyad bin Abi Al-Ja'd took me by the hand while we were in Ar Raqqah, he made me stand before a Shaikh who was called Wabisah bin Ma'bad, from Bani Asad. Ziyad said: 'This Shaikh narrated to me that a prayed alone behind the row' - and the Shaikh was listening - 'so Allah's Messenger ordered him to repeat the Salat