Musannaf Ibn Abi Shayba 3:891

Ibn ‘Ulayyah narrated to us, from ‘Awf, who said: Abu al-Minhal narrated to me, saying: I arrived with my father to Abu Burdah. He said: "Narrate to us how the Messenger of Allah (peace and blessings of Allah be upon him) used to pray the obligatory prayer." He said: "He used to pray the *Hajir*—which you call the *Ula* (the first)—when the sun declines."