It was narrated that 'Abdur-Rahman bin Yazeed said: 'Abdullah (رضي الله عنه) said:

I never saw the Messenger of Allah (ﷺ) offer any prayer that was not on time except in two cases: Maghrib and 'Isha' in Muzdalifah, and he prayed Fajr on that day before the time when he usually prayed it (but after ascertaining that dawn had broken).