كتاب الصلاة
2  
The Book of Prayer
Bulugh al-Maram 156
Narrated Abu Musa (RA) in another version of Muslim:
He (ﷺ) offered the Fajr prayer at daybreak when the people could hardly recognize one another.
وَلِمُسْلِمٍ مِنْ حَدِيثِ أَبِي مُوسَى: { فَأَقَامَ اَلْفَجْرَ حِينَ اِنْشَقَّ اَلْفَجْرُ, وَالنَّاسُ لَا يَكَادُ يَعْرِفُ بَعْضُهُمْ بَعْضًا }
Reference : Bulugh al-Maram 156
In-book reference : Book 2, Hadith 156
English translation : Book 2, Hadith 156
Hadith Text
Reference