Sunan An-Nasai, Chapter: The Book of the Times (of Prayer)

"I entered upon Abu Barzah, and my father asked him: 'How did the Messenger of Allah (saw) pray the prescribed prayers?' He said: 'He used to pray Zuhr, which you call Al-Uula (the first) when the sun passed its zenith; he used to pray Asr when one of us could go back to his home in the farthest part of Al-Madinah while the sun was still bright.' I forgot what he said about Maghrib. And he used to like to delay the Isha, which you call Al-Atamah, and he did not like to sleep before it nor talk after it. And he used to finish the Al-Ghadah (Fajr) prayer when a man could recognize his neighbour, and he used to recite (in it) between sixty and one hundred verses.'" (Sahih)