15. The Book of Pilgrimage

١٥۔ كتاب الحج

15.48 It is recommended to pray Subh when it is still dark on the day of sacrifice in Al-Muzdalifah, and to do it very early after ascertaining that dawn has broken

١٥۔٤٨ باب اسْتِحْبَابِ زِيَادَةِ التَّغْلِيسِ بِصَلاَةِ الصُّبْحِ يَوْمَ النَّحْرِ بِالْمُزْدَلِفَةِ وَالْمُبَالَغَةِ فِيهِ بَعْدَ تَحَقُّقِ طُلُوعِ الْفَجْرِ

(811) bukhari:1682ʿUmar b. Ḥafṣ b. Ghiyāth from my father > al-Aʿmash > ʿUmārah > ʿAbd al-Raḥman > ʿAbdullāh

I never saw the Prophet ﷺ offering any prayer not at its stated time except two; he prayed the Maghrib and the ʿIsha' together and he offered the morning prayer before its usual time.  

(٨١١) البخاري:١٦٨٢حَدَّثَنَا عُمَرُ بْنُ حَفْصِ بْنِ غِيَاثٍ حَدَّثَنَا أَبِي حَدَّثَنَا الأَعْمَشُ قَالَ حَدَّثَنِي عُمَارَةُ عَنْ عَبْدِ الرَّحْمَنِ عَنْ عَبْدِ اللَّهِ ؓ قَالَ

مَا رَأَيْتُ النَّبِيَّ ﷺ صَلَّى صَلاَةً بِغَيْرِ مِيقَاتِهَا إِلاَّ صَلاَتَيْنِ جَمَعَ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ وَصَلَّى الْفَجْرَ قَبْلَ مِيقَاتِهَا