Musnad Ahmad 594:7

Yahya ibn Sa'id narrated to us, from Shu'bah, 'Amr ibn Murrah narrated to us, from Hilal ibn Yasaf, from 'Amr ibn Rashid, from Wabisa: "That the Prophet, peace and blessings of Allah be upon him, saw a man praying in the row alone, so he commanded him to repeat the prayer."