(99) باب مَنْ يُصَلِّي الْفَجْرَ بِجَمْعٍ
Narrated `Abdullah:
I never saw the Prophet (ﷺ) offering any prayer not at its stated time except two; he prayed the Maghrib and the `Isha' together and he offered the morning prayer before its usual time.
Reference: Sahih al-Bukhari 1682
In-book reference: Book 25, Hadith 162
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 26, Hadith 742