Sunan at-Tirmidhi (Jami-al-Tirmidhi), Chapter: Salah (Prayers)

that the Prophet (SAW) said, "Jibril led me in Salah twice near Bayt Allah. The first time, we offered the Salah of Zuhr when the shadow was like the thong of a shoe. Then, we offered Asr when the shadow of everything was equal to it, and maghrib after sunset when the fasting man takes iftar (breaks his fast), and Isha when the twilight disappeared, and fajr when one who fasts is forbidden food and drink. The second time, we offerred Zuhr when the shadow of everything was like it in length at the time of Asr on the previous day. Then we offered the Asr when the shadow of everything was twice as long. We prayed Maghrib at the same time as the previous day; we prayed Isha when one-third of the night was over and Fajr when the earth was well-lit. Then Jibril turned to me and said; "O Muhammad! This was the time observed by Prophets before you, and the time (of five Salah) is between these two times." [Ahmed 3081, Abu Dawud 393]