Sahih Bukhari | Volume 1 | Hadith Number 516
Narrated by Abu Al-Minhal
Abu Barza said, "The Prophet used to offer the Fajr (prayer) when one could recognize the person sitting by him (after the prayer) and he used to recite between 60 to 100 Ayat (verses) of the Qur'an. He used to offer the Zuhr prayer as soon as the sun declined (at noon) and the 'Asr at a time when a man might go and return from the farthest place in Medina and find the sun still hot. (The sub-narrator forgot what was said about the Maghrib). He did not mind delaying the 'Isha prayer to one third of the night or the middle of the night."