Sahih Bukhari Volume 002, Book 026, Hadith Number 743.
Narated By 'Abdur-Rahman bin Yazid : I went out with 'Abdullah , to Mecca and when we proceeded to am' he offered the two prayers (the Maghrib and the 'Isha') together, making the Adhan and Iqama separately for each prayer. He took his supper in between the two prayers. He offered the Fajr prayer as soon as the day dawned. Some people said, "The day had dawned (at the time of the prayer)," and others said, "The day had not dawned." 'Abdullah then said, "Allah's Apostle said, 'These two prayers have been shifted from their stated times at this place only (at Al-Muzdalifa); first: The Maghrib and the 'Isha'. So the people should not arrive at Al-Muzdalifa till the time of the 'Isha' prayer has become due. The second prayer is the morning prayer which is offered at this hour.' " Then 'Abdullah stayed there till it became a bit brighter. He then said, "If the chief of the believers hastened onwards to Mina just now, then he had indeed followed the Sunna." I do not know which proceeded the other, his ('Abdullah's) statement or the departure of 'Uthman. Abdullah was reciting Talbiya till he threw pebbles at the Jamrat-al-'Aqaba on the Day of Nahr (slaughtering) (that is the 10th of Dhul-Hijja).