Abdur-Rahman bin 'Ali bin Shaiban narrated that his father Ali bin Shaiban, who was part of the delegation, said: "We set out until we came to the Prophet P.B.U.H. We gave him our oath of allegiance and performed prayer behind him. Then we offered another prayer behind him. He finished the prayer and saw a man on his own, praying behind the row." He said: "The Prophet of Allah P.B.U.H stood beside him and when he finished he said: 'Repeat your prayer; there is no prayer for the One who is behind the row:" (Sahih)