Sunan an-Nasa'i #521

"A man came to the Messenger of Allah (ﷺ) and asked him about the times of prayer. He said: 'Stay with us for these two days.' Then he told Bilal to say the Iqamah at dawn and he prayed Fajr. Then he told him to do that when the sun had passed its zenith and he prayed Zuhr. Then he told him to do that when the sun was still bright, and he said the Iqamah for 'Asr. Then he told him to do that when the last part of the sun had dissapeared, and he said the Iqamah for Maghrib. Then he told him to do that when the twilight had disappeared and he said the Iqamah for 'Isha'. The following day, he prayed Fajr when there was light, then he delayed Zuhr until it was cooler, and waited until it was much cooler before praying 'Asr but the sun was still clear, so he prayed 'Asr later than on the first day. Then he prayed Maghrib before the twilight disappeared. Then he told him to say the Iqamah for 'Isha' when one-third of the night had passed, and he prayed, then he said: 'Where is the one who was asking about the times of prayer? The times of your prayer are between the times you have seen.'"