Musannaf Ibn Abi Shayba 3:2892

Abu Bakr narrated to us, he said: Abd al-Wahhab al-Thaqafi narrated to us, from Ayyub, from Muhammad, that an amir in Bahrain complained [of illness], so he ordered a man, and he led the people in prayer and did not deliver a khutbah, and he prayed four [rak'ahs]. Muhammad said: He hit upon the Sunnah.